About music4dance

Battle of the Bands – no, I mean Battle of the Bots :-(

If you visited music4dance.net in the last week of October (between about October 23rd and 26th), you probably noticed it was very sluggish, possibly even completely unresponsive. I’m very sorry if that affected you. The timing was particularly unfortunate for a couple of reasons. First, this happened while I was on vacation overseas, traveling with only an iPad to diagnose and resolve issues. Second, it was the week leading up to Halloween, so DJs using music4dance to build or enhance their Halloween Playlists were justifiably frustrated. Thanks for bearing with me. All the emails I got reporting the outage were very kind, and I appreciate that you took the outage in stride.

What Happened?

While I was on vacation overseas, I noticed the server was rebooting several times a day, which was unusual. But whenever I checked, things were working. Since the server is in the western US and I was in South Korea, I attributed the latency to geographic issues.

It wasn’t until you started emailing me that I took some time out to log in and investigate.

Despite the title of this post (which I couldn’t resist), the proximate cause of this outage wasn’t bot traffic like the ones I’ve blogged about before, or the attempts to hack the site, which I didn’t end up blogging about. It was due to memory pressure on the very small virtual computer running the website in the cloud. It happened because my hosting provider replaced the operating system/libraries underneath me with a version that changed behavior (possibly due to a bug) and caused some kind of memory leak.

But it would not have been as severe, or may not have happened at all, if over 90% of the traffic coming to the site (and causing pressure) wasn’t bot traffic of some sort. The direct human traffic probably wouldn’t have stressed the server enough to cause downtime, even with the bug.

This is part of a larger trend for small, independent websites. Here are a few articles about that trend, if you’re interested:

What did I do?

The immediate fix, which I could perform from an iPad (ironically – because I had AI to do the heavy lifting), was to scale up to the next biggest virtual machine that my host supports. At the very low end of the cost spectrum, that meant I ended up doubling the available resources. That immediately mitigated the issue,  and the site stopped crashing. But double the resources means double the cost, which I would prefer not to sustain indefinitely.

When I got back home, I spent some time looking into other ways to mitigate the issue. I’d already invested quite a bit in recognizing and ignoring malicious bots and improving my code’s resilience. Because of that work, the server could restart and reconnect reliably without human intervention, and even while on vacation, I could diagnose and mitigate an issue like this.

I also discovered during the investigation that there were several cheap things I could do to reduce the size of the web pages my server returns, which helped quite a bit.

But I hadn’t taken the next obvious step: adding an edge network between the internet and my website to filter traffic, mostly because the lowest-cost version my hosting provider offered came with a minimum monthly fee greater than my server cost (even the bigger version I’m running right now). On further investigation, Cloudflare has a free offering that looks like it will fit the bill. I’ve put that in place and am tuning up their bot protections and other methods to mitigate many of the issues that have been plaguing the site recently. If that works, I might even feel comfortable scaling back to the smallest available server and returning to the monthly cost I was shelling out before this incident.

What this costs me

As I said in March, music4dance has never paid for itself. I cover the costs, and I’ve been happy to, because the site is a labor of love. But I want to be transparent about where the time and money go:

  • Server cost doubled. The bigger server costs about twice as much as the old one. This isn’t a full doubling of the hosting cost, since I didn’t have to increase the size/capacity of the resources beyond the server instance, but it’s still significant.
  • Bandwidth is billed by the gigabyte, and the site was sending out several gigabytes a day, mostly to robots. The changes above cut that substantially, so I hope this won’t be an issue moving forward.
  • The biggest cost is time. I’ve been spending well over half the time I devote to music4dance resolving issues like these or building out infrastructure to (hopefully) avoid them coming up in the first place. This is time I’d rather spend adding new features, curating the catalog, and responding to all the interesting questions I get from you. Or writing posts about the relationship between music and dance, rather than posts like this one.

How you can help

  • If you use music4dance regularly and haven’t subscribed, please consider it. Subscriptions should be what keep the lights on, and more subscriptions would directly offset costs like these.
  • Tell me when the site is slow or broken, and what page you were on. Reports from real people are still the best early warning I have.
  • Keep sharing the site. As I said in March: the last thing I want is for usage to go down as the solution. I’d just rather the visitors be dancers than robots.

I appreciate your patience and your support in this adventure.

Step of the Month

The  “Step of the Month” for November is to please spread the word – let a fellow dancer or DJ know how much you get out of music4dance and encourage them to give it a try. Or pass along your favorite post (hopefully one about a feature or something fun rather than this one).

Is music4dance becoming too popular?

I first published music4dance in 2013 and, within a year or so, started seeing traffic measurable in the thousands of active users per month. Usage plateaued there for over a decade, but last year, the numbers started climbing rapidly – into ranges better measured in tens of thousands. Now these are very rough measures from…

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Bug Report

Bug Bounty: We would like to provide a reward to people who take the time to report bugs. So for each bug that you report that hasn’t been reported by others, we will give you a week of our premium service for free (or extend an existing premium membership by a week). We must be…

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About music4dance

New Feature: Copy Link to This View, or how to share a tempo table

In my post about automatic tempo correction, I asked for help with the tempo thresholds, and I included a link that opened the tempos page with just the Meter, BPM, and Range columns showing. I promised to explain “that little trick in a future post.” This is that post, but the trick has changed since I wrote that.

In August, the only way to get a link like that was to know the parameter names and type them into the address bar, which is what I did. Now I don’t have to. The Dance Tempi page and the Tempo Counter each have a new button that copies a link to exactly what you’re looking at.

The easy way: Copy Link to This View

The Dance Tempi page with the Type dropdown set to Latin and the other filters at All. Below the filter box is a Copy Link to This View button, then a table of eleven Latin dances, from Bachata to Samba, with Name, Meter, BPM, and Range columns. Only Bachata, Bolero, and Salsa show a range.
The Dance Tempi page, filtered to the Latin dances with the Range column showing. The Copy Link to This View button sits just above the table.

Set up the Dance Tempi page however you like: pick styles, types, meters, and organizations from the dropdowns, and choose which columns to show. Then click Copy Link to This View, just above the table. The link goes to your clipboard, ready to paste into an email, a text, or a post on your studio’s Facebook page. Whoever opens it sees the same table you did. The image above is this link.

The address bar also updates as you change things, so bookmarking the page does the same job as copying the link. If you leave everything at the default, there’s nothing to add, and the link is just the plain page address.

The Tempo Counter set to Count Measures, showing 120.0 BPM and 30.0 MPM in 4/4. A Copy Link to This Tempo button sits above a list of matching dances: Slow Foxtrot, Tango, Cha Cha, Rumba, and West Coast Swing, each with its range in measures per minute followed by (4/4).
The Tempo Counter at 30 measures per minute in 4/4, with the Copy Link to This Tempo button above the list of matching dances.

The Tempo Counter works the same way, with a button labeled Copy Link to This Tempo just above the list of dances. Once you’ve tapped out or typed a tempo, the link captures the tempo, the meter, whether you’re counting beats or measures, and where the strictness slider is set. That’s handy if you’ve worked out the tempo of a song and want to show a partner or a student which dances fit it. The image above is this link.

The same idea is also on the song search pages: search results and the advanced search form now have a Copy Link to This Search button.

Building a link by hand

You don’t need any of this to use the buttons. But if you’re writing a web page or a handout and want to type a link straight into it, both pages take a handful of parameters:

  • The Dance Tempi page takes styles, types, meters, organizations, and columns, which match its four filters and its column chooser.
  • The Tempo Counter takes tempo (always in beats per minute), numerator (the beats per measure), count (beats or measures), and epsilon (where the strictness slider is set).

Every parameter is optional, and anything a page doesn’t recognize is quietly skipped rather than producing an error page. The full lists of values and defaults, with examples, are in the “Building a link by hand” sections of the Dance Tempi and Tempo Counter help pages, which I rewrote for this feature.

For the record, the link from the August post was https://www.music4dance.net/Home/Tempi?columns=meter&columns=bpm&columns=validationRange. The columns parameter lists every column to show, and validationRange is the Range column, which is hidden by default.

Two fixes to the Tempo Counter

Rewriting the Tempo Counter help page meant actually trying everything it describes, and that turned up two bugs:

  • With the strictness slider all the way to the left, toward less, the list was always empty, even when your tempo was squarely inside a dance’s range. The far left now shows exactly the dances whose range includes your tempo.
  • The dances in the list had lost their meter. That matters because in 4/4 the counter also lists the 2/4 dances, and their ranges are in 2/4 measures, which run twice as fast. Without the “(2/4)” after the range, Samba at 48-52 MPM looked like a terrible match for 24 MPM in 4/4, when it’s actually spot on. The meter is back.

What it doesn’t do

This is the incremental version, so there are a couple of gaps. The Filter Dances search box on the Dance Tempi page isn’t part of the link, and neither is the column you sorted by, so a shared table always opens sorted by name. If you run into a view you can’t link to, or a link that doesn’t open what you expected, please let me know.

Step of the Month

The  “Step of the Month” for October is to help out with the Halloween catalog. There are several ways to do this: you can add the Halloween Tag to songs that don’t have it and should, you can remove the Halloween Tag from songs that do have it and shouldn’t, or you can add new Halloween songs (I will also accept lists of songs if that’s easier – in that case, please reach out for details on accepted format).

AI disclosure: I used AI to write the first draft of this post, then edited it and take responsibility for what it says. How AI is used on music4dance.

New Feature: Automatic Tempo Correction by Dance

One of the cool things about maintaining a database of songs cataloged by dance is that I can use that information to correct the most common mistake made by algorithmic tempo matching: the double-time/halftime issue. I’ve done this on an ad hoc basis for years, but now I have everything lined up so the system…

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Music and Dance, Special Occasions

Songs for Halloween Ballroom and Partner Dances – 2026 edition

We continue to add to the music4dance Halloween song catalog. As of this writing, 1649 songs are tagged as Halloween and have a positive number of dance votes. Up nearly 500 songs from last year.

This year, rather than repeating information about how the catalog works or the motivations for how I’ve set up the pages (you can see that in previous Halloween posts), I’d like to focus on where I’ve overshot. What I mean by that is that I’ve pulled in songs labeled Halloween from many different sources. Since the catalog defaults to ordering by total dance votes, that puts things like Christina Aguilera’s “Candyman” at the top of the list. This isn’t obviously a Halloween song. It’s definitely not spooky. It may be useful at a Halloween dance to throw in a peppy Swing as a palate cleanser between spooky songs. Or it may be that it’s a fun song to do an exhibition dance to in costume.

The Dancing With The Stars Issue

In fact, one of the reasons “Candyman” ended up on the music4dance Halloween list is that it was featured in DWTS season 27’s Halloween episode. I haven’t been very consistent about cataloging DWTS music, but I’ve done enough that it contributes to the issue when I tag something as Halloween just because it’s on one of their Halloween episodes. I could fix this by retroactively changing all the DWTS Halloween tags to “Halloween Night” tags. Then I could manually go through and re-add Halloween to anything that I think qualifies. Or I could hope others do that over time.

A small detour into searching

I was going to provide a list of songs DWTS labeled as “Halloween,” but I realized this is another case of having the right data but not properly indexed for this task (and I’d run out of space if I indexed all tags this way). But it’s pretty much the same case as the dance votes by a specific user, where I pull the first chunk of the list (which is often the whole list) into memory and then filter it down.

But that’s not all

But DWTS isn’t the only list that the Halloween Tag came from. At one point, one of the generic Spotify-generated lists included that song, as well. So focusing too much on DWTS may not be the right move. And while I may be totally off-base and everyone else thinks “Candyman” qualifies as a Halloween song, plenty of other examples seem pretty suspicious.

So maybe the answer is to go through the Halloween songs and just clear that tag from anything that doesn’t seem particularly Halloweeny. What do you think? My general bias has been to pull in more songs and tags to give as broad a base as I can for browsing for ideas, then leave it as an exercise for you to do that last level of filtering. But in some cases (quite possibly this one) the signal can be drowned out by the noise.

Indexing on number of Halloween Votes

One possible mitigation is to index on the number of Halloween votes and default the sort to that rather than the dance votes. I could do something similar for Holidays. This would cause a combinatorial explosion if I indexed all tags, but I could probably do it for Halloween and Holiday (and maybe a few other interesting ones).

What now?

It’s too late for me to make major changes to the code before Halloween (especially far enough before Halloween to help people trying to put together playlists for Halloween dances). And I’m going to leave the specific catalog asks for the step of the month. But I would like your input on some broader questions that stem from the above, so please feel free to respond to this post or use any method listed on the feedback page to answer any or all of the following questions.

  • Should I remap DWTS “Halloween” songs to “Halloween Night” and exude them from the Halloween pages?
  • While I’m on DWTS, do you find these entries useful? Would you like me to do more complete cataloging of DWTS entries, or pull back further?
  • Do you think I’m pulling in too much? Would you prefer a smaller, more highly curated catalog than what I’m doing now?
  • If you read the aside, should I expand the Dance Vote per-user filter to include tag per user? e.g., let me search for all songs that DWTS tagged as “Halloween” and not pick up songs that DWTS contributed to in some other way, or that a different user tagged as “Halloween.”
  • Can you think of anything else I could do to improve the Halloween or Holiday catalogs? There might still be time to improve the Holiday catalog [link] for this season.

Step of the Month

The  “Step of the Month” for October is to help out with the Halloween catalog. There are several ways to do this: you can add the Halloween Tag to songs that don’t have it and should, you can remove the Halloween Tag from songs that do have it and shouldn’t, or you can add new Halloween songs (I will also accept lists of songs if that’s easier – in that case, please reach out for details on accepted format).

Songs for Halloween Ballroom and Partner Dances – 2025 edition

We continue to add to the music4dance Halloween song catalog. As of this writing, there are 1151 songs tagged as Halloween with a positive number of dance votes. As I’ve noted in previous posts, we’ve gone from using the general tagging mechanism where you could search on songs that had a musical genre of “Halloween”…

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Halloween Ballroom Music 2024

Halloween is fast approaching, and I’m updating the music4dance Halloween catalog to include more partner dance Halloween music. I’ve pulled some generic Halloween playlists and cross-referenced them with the existing music4dance catalog. Using this method and some help from the community, we now have 340 songs available in the Halloween catalog that are also tagged…

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New Feature: Searching for only the songs that someone has voted for

Arne pointed out the other day that it would be useful to be able to build a playlist for just the songs that he had voted for dancing Cha Cha. I scratched my head a bit because I thought this was already possible. I even added a feature last year to make it easier to see who has voted on dance styles…

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About music4dance

New Feature: An Artist Index, or what else has Kenny Rogers done?

In my last post, while working through the ways music4dance does and doesn’t handle artists, I wrote that I was “pretty sure I’ll implement an Artist Index of some kind in the foreseeable future.” It turns out that the foreseeable future was about ten days. The artist index is live, under Music → Artists.

Browsing

The music4dance artist index page: a search box, an A-to-Z letter navigation row, and four columns of artist names, each followed by its song count.
The artist index, opened to the artists with the most songs in the catalog.

The page starts with the hundred artists who have the most songs, which is interesting in its own right — the top of that list is as much practice/ballroom orchestras as it is the names you’d expect. From there you can type any part of a name into the search box or click a letter to browse. As of this writing, there are 15,093 artists in the index; the 5,986 of them with more than one song are the ones you see by default, and there’s a link to include the rest.

Artists rather than credits

The part of this feature that I think matters more is what happened to the artist pages themselves.

Until now, an artist page matched the whole artist field as a phrase, so the Dolly Parton page listed the songs credited to exactly “Dolly Parton” and nothing else. That’s why, in the last post, the best I could offer for “Islands in the Stream” was a link to an advanced search. Now the system reads each credit and pulls the individual artists out of it, so that song sits on Dolly Parton’s page and on Kenny Rogers’ page, and both halves of the credit are links wherever it appears.

Image of the Dolly Parton artist page

Her page picked up four songs it didn’t have before, plus an “Also appears with” line pointing at Kenny Rogers, Ricky Van Shelton, Vince Gill, and Willie Nelson. The credit itself is never rewritten — the song details page still shows exactly what the source said.

This also cleans up the case I’ve been frustrated with since 2016. The Prince pate is now 28 songs, including the ones credited to Prince & The New Power Generation, and Prince Royce is a separate entry in the index with 53 songs of his own, rather than something I have to apologize for in the middle of a search.

Where it falls short

Unsurprisingly, a free-text artist field doesn’t give up its contents easily. I only split a credit where there’s real evidence for it — a “feat.” or a slash, or a name that already carries songs of its own — because the failure I least wanted was a band name torn in half.

The bigger limit isn’t the splitting, though. When I measured our credits against a sample of Spotify’s structured ones, about 28% of the credits in the catalog turn out to involve more than one artist — but 80% of those credit strings contain no separator at all. Spotify knows a song is by two people; our copy of the credit just says the first one. No amount of cleverness gets a name out of a string it isn’t in, so this picks up roughly a fifth of the collaborations that are really out there. Closing the rest of that gap means going back to the services for better data, which is a project for another day.

A couple of smaller things: spelling variants are still separate artists, so P!nk and Pink each have a page, and the index itself rebuilds every few hours, so a brand-new song can take a little while to turn up there (the artist pages are current immediately). And the larger caveat from last time still stands — the artist field is still text, not a proper relational thing with artists as first-class objects. This is the incremental version. It just turns out the incremental version covers most of what I actually wanted.

If you’d like to help

The Artists help page has the full details, including how to correct an artist list on a song. If you land on a page with songs that don’t belong there, or find a credit that clearly should have been split and wasn’t, please let me know. And if you’d enjoy doing some of that cleanup yourself, send me your music4dance username and I’ll turn on editing for your account.

Step of the Month

The  “Step of the Month” for September is still the ask from the last post: which Dolly Parton songs are your favorites to dance to, and what style of dance? I’m particularly interested in hearing from Country Western dancers. Feel free to respond to this post, use the general feedback page, or add the songs and vote on existing songs directly. Her page is a better place to start than it was two weeks ago.

AI disclosure: I used AI to write the first draft of this post, then edited it and take responsibility for what it says. How AI is used on music4dance.

Artists

Every song in the music4dance library carries an artist credit exactly as its source song wrote it — Pitbull feat. Ne-Yo, Duke Ellington and His Orchestra, Dolly Parton & Kenny Rogers. That’s the right thing to display, but it’s an awkward thing to browse. If you wanted to know what else Kenny Rogers had recorded,…

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What Are Your Favorite Dolly Parton Songs for Partner Dancing?

Like many, I’m mourning and listening to Dolly Parton’s music. I haven’t written a post related to an artist’s death since Prince left us in 2016. I’m not sure what my internal algorithm is for this, but besides Dolly being such a unifying cultural icon, there is the small detail that I noticed a significant…

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What are your favorite Prince songs for partner dancing?

Update 2024: The content of the post is still generally accurate. There is a more recent post that outlines a new feature that adds yet another way to narrow down songs that have “Prince” in the artist’s name. New Feature: Improved Text Searching I, like many, am mourning and listening to Prince’s music. Over and…

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Searching for Music

What Are Your Favorite Dolly Parton Songs for Partner Dancing?

Like many, I’m mourning and listening to Dolly Parton’s music. I haven’t written a post related to an artist’s death since Prince left us in 2016. I’m not sure what my internal algorithm is for this, but besides Dolly being such a unifying cultural icon, there is the small detail that I noticed a significant uptick in people searching music4dance for “Dolly Parton” over the last few weeks. I don’t have a good way to track statistics on this kind of search, but it was significant enough that random viewing of my diagnostic logs for other issues kept popping up her name. Qualitatively, that’s pretty amazing and hasn’t happened before.

So, as the title says – which of her songs are your favorites to dance to? And what style of dance? I’m particularly interested in hearing from Country Western dancers, since I don’t have enough background in those dances to categorize them myself. Feel free to respond to this post, use the general feedback page, or add the songs/vote on existing songs directly. I’d love to see this part of the catalog grow as our small tribute to her memory.

Searching for Artists

As I reviewed Dolly Parton songs, I took another look at how I catalog artists in music4dance. This is similar to what happened when I dug into Prince songs in 2016. In both cases, a review highlighted some of the limitations of that process.

For Prince, I improved the process by adding a feature that showed all the songs with an artist field containing exactly “Prince.” That narrowed down the results to only his songs. But it was a bit too narrow in that it excluded songs where the artist field contained a band name or a collaborator. But as in much of this work, I aim for incremental improvement and wait for feedback before investing more time.

A few years back, I returned to the searching for artist issue due to another spike in artist searches – this one for a different reason – Dancing With the Stars aired episodes featuring the music of Whitney Houston and Taylor Swift. Initially, I wrote a blog post about what I saw as the limitations, but asked for feedback before proceeding.

A few months later, I implemented improved text searching based on that feedback, adding more capabilities to chip away at the problem. In the case of Dolly Parton, you could now search for all songs that contain Dolly Parton in the artist field. That pulls in everything you see on the Dolly Parton artist page, as well as collaborations with Kenny Rogers, Vince Gill, Willie Nelson, etc. But not songs that have Dolly in the title, like the multiple versions of Hello Dolly! It’s a little less successful for Prince, mostly because other artists such as Prince Royce show up in that search.

An Incremental Improvement

The other issue is that you have to know about the advanced search option for this to work at all. I decided to make an incremental improvement to discoverability. When you land on the Dolly Parton page, it implies the page will list all the Dolly Parton songs in the catalog. So I added a link near the top of the page –Search all songs with “Dolly Parton” in the artist field – to indicate that there may be more Dolly Parton songs available and to provide a smooth path for getting to that list.

What Next?

I think the two biggest remaining gaps are some form of Artist Index and the fact that I’m still keeping the artist field as free text rather than setting up a relational database where artists are a first-class object and songs can be related to multiple artists.

Now that I’m thinking about this again, I’m pretty sure I’ll implement an Artist Index of some kind in the foreseeable future. I’m unlikely to tackle the relational database solution anytime soon, but I might make incremental improvements to how I handle the artist field.

What do you think? Do you run into issues searching for artists? Or are there other improvements to search or elsewhere that you would prioritize over these? Feedback is always welcome.

Step of the Month

The “Step of the Month” for September is the same as the ask at the beginning of this post. Which Dolly Parton songs are your favorites to dance to? And what style of dance? Feel free to respond to this post, use the general feedback page, or add the songs/vote on existing songs directly. I’d love to see this part of the catalog grow as our small tribute to her memory.

New Feature: Improved Text Searching

I’ve always been a bit dissatisfied with how I set up the Artist field in music4dance.  A free text field for the artist generally works, but it doesn’t capture everything I’d like.  But since the core functionality of music4dance is to associate songs with dance styles, keeping the rest of the system simple is a…

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What are your favorite Prince songs for partner dancing?

Update 2024: The content of the post is still generally accurate. There is a more recent post that outlines a new feature that adds yet another way to narrow down songs that have “Prince” in the artist’s name. New Feature: Improved Text Searching I, like many, am mourning and listening to Prince’s music. Over and…

msc4dnc's avatar by msc4dnc

Ballroom Dancing to Whitney Houston and Taylor Swift

The recent Dancing With the Stars episodes featuring Whitney Houston and Taylor Swift’s music caused a significant spike in traffic at music4dance.net, with dancers looking for music by those artists. I find this exciting for many reasons.  There’s the obvious reason that more traffic means more people showing interest in this project.  It also reinforces…

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About music4dance

New Feature: Automatic Tempo Correction by Dance

One of the cool things about maintaining a database of songs cataloged by dance is that I can use that information to correct the most common mistake made by algorithmic tempo matching: the double-time/halftime issue. I’ve done this on an ad hoc basis for years, but now I have everything lined up so the system can make these adjustments automatically.

One of the major blockers was that I was only maintaining one tempo per song. To do this right, I’d need to keep different tempos for every dance a song can be danced to, which was a major feature I implemented earlier this summer. So I decided it was time to take another look at automatically adjusting the tempo based on the dance.

The Feature

The general idea is to have two thresholds. One is the tempo under which it is clear that the listed tempo is half-time of what one would dance that specific dance to. The other is the tempo where it is clear that the listed tempo is double time. These are related to the subject of my last post. Although, in this case, there may not be a dance one would dance to the listed tempo. But there might be, which is where things get interesting.

When a song is added to the catalog or a new dance style is added to an existing song, the system checks if I’ve defined threshold tempos for the dance. If I have, and the song’s tempo is below or above the threshold, I double or halve the tempo, respectively. There are some additional nuances depending on whether other dances are already defined. But with the tempo-per-dance system, I can ensure that changing the tempo of one dance doesn’t affect the others. I do change the song’s default tempo if all dances define the same tempo. Sometimes this ends up listing the song’s tempo as half or double what the sheet music says, but since music4dance is a dance-oriented site, I’m all right with that.

Note that, in line with my current policy of trusting community members over algorithms, all of these changes are made using the “tempo-bot” account and can be changed by any signed-in community member.

Please Help

Why am I telling you all this? Because I am not an expert in all of the dances I have listed on music4dance. And even for those I have some experience with (or can at least stumble through on the dance floor), it’s through my personal lens, which may not be the same as yours.

If you’ve got a minute, please go to the tempos page (Tools → Tempi) and scroll down to the columns control. There is a new column called Range; go ahead and select that. When I’m looking at this info, I generally deselect all other columns except Meter and BPM to get a cleaner picture. Or click here to get directly to the page with the columns correctly configured. (More about that little trick in a future post).

Snapshot of the tempos page with columns set up to highlight range.

I’d like to know your take on what these thresholds should be for both the dances I’ve felt confident enough to set (sometimes based on data rather than personal knowledge) and those I haven’t pulled the trigger on.

Waltzes

I started to call out why waltzes are in a class of their own, but decided that’s worth a post of its own; look for that soon.

Dances that are primarily Social

Some dances, like West Coast Swing and Salsa, are primarily social dances. I know there are competitions for them as well, but they’re so broadly and actively danced socially that I think they’re evolving faster than the dances that I’m familiar with that have more of a center around competition with strict tempo rules.

In the case of West Coast Swing, I made the mistake of centering around the tempos that I’ve danced in competition. Based on feedback and additional research, I ended up listing it with such a broad range that I don’t think I can use the range-limiting technique on it at all.

In the case of Salsa, there were enough half-time songs to find a reasonable breakpoint. I’d love to hear from Salsa dancers and DJs if I’m wrong.

And I’m completely out of my depth with Argentine Tango and related dances, so if there is anyone out there willing to help with those, I would really appreciate any guidance you can give.

In short, I could really use some help on this one. Please comment on this post or send feedback if you can help.

Step of the Month

The “Step of the Month” for August:  This is a small variation on the July Step. Please share an unusual rhythm song (or songs) that you enjoy dancing to. I’m specifically looking for interesting variations that I haven’t mentioned yet in the Fun Rhythms series. I’ve got one more up my sleeve, but I’d like to continue on this path for more than three posts. But I need some help to do that. Post it in the comment thread here or send feedback.

Fun Rhythms: 12/8 meter- Slow Foxtrot + Viennese Waltz?

Since I’ve added the ability to set the tempo of a dance for a song independently of the tempo of the song itself, I’ve found some renewed energy to go through and clean up some of the inconsistencies that have crept into the music4dance catalog. As I promised (or threatened) when I blogged about the…

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What Happens When a Song is Danced at Different Tempos?

Sometimes, a song can be a perfectly good Bolero when heard one way but a Salsa when counting the music differently. Another example is Slow Dance (Castle Foxtrot) vs. Lindy Hop. Generally, this phenomenon is because, with some music, it’s easy to count what the musicians see as either a half note or a quarter…

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Ask music4dance: Why are the tempos that music4dance lists for Salsa wrong?

I’ve addressed questions about tempo in several different ways over the years, and I appreciate the continued feedback, as there is absolutely room for improvement in how the music4dance system handles tempo. Algorithms are far from perfect: The issue at hand is that many of the tempos listed for Salsa were exactly half the speed…

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Ask music4dance: Why is the tempo range you list for West Coast Swing wrong?

A West Coast Swing DJ contacted me and kindly let me know that the tempo range I had listed for West Coast Swing was “entirely wrong.” The average tempos that she plays are between 90 and 110 bpm, while I listed a tempo range of 112-128 bpm.  Before I dig further into the details, I’d…

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Music and Dance

Fun Rhythms: Half-time/Double-time – Dancing a Jive and a Slow Foxtrot to the same song

In the first post in this series, I talked about the 12/8 meter. And how, at certain tempos, that allows dancers to legitimately hear a very slow Foxtrot rhythm while someone else (or the same person tuning their ear a little bit differently) can hear and dance to a fast Viennese Waltz. This is one of my favorites, but it is pretty rare.

This time I’d like to touch on the much more common cases of half- and double-time rhythms. Musically, this can be when one person is counting quarter notes, and someone else is counting eighth notes; the second is double-time (or double the tempo) of the first. Or one person hears quarter notes, and the other hears half notes, that being half-time (or half the tempo) of the first.

Bam Bam:

One example of this is Bam Bam by Camila Cabello – One can dance a fast Salsa to that song at 190 beats per minute, or a slow Cha Cha at 95 beats per minute. If you take a look at the sheet music, the official meter is 4/4 with a tempo of a quarter note = 96 beats per minute. But you can also see that most of the melody line is sixteenth notes, and the bass line is dominated by eighth notes, so you can see a potential double-time rhythm.

But more importantly, if you listen to the recording (Spotify or Apple Music), there is a snare drum that’s consistently hitting eighth notes (exposing a 190 bpm tempo), and the actual bass guitar is predominantly playing quarter notes (exposing a 95 bpm tempo).

You Can’t Hurry Love:

In Phil Collins’s You Can’t Hurry Love, the sheet music is listed at 96 bpm. But the bass guitar is playing fairly strong and consistent eighth notes, so the majority of the music4dance community has heard this at double the listed tempo (196 bpm) and voted to dance Quickstep, Single Swing, or Jive to it.

But there is a very strong tambourine on beats two and four that brings out the quarter-note tempo and allows one to hear the 98 bpm natural tempo and dance a Slow Dance or Slow Foxtrot to the same song.

An aside – small discrepancies in tempos:

If you were following along closely, you’ll notice that the listed sheet music tempos are slightly different than the “listening” tempos that are on Music4Dance, even allowing for double-time/half-time considerations. e.g., Bam Bam is listed at 96 bpm in the sheet music, but I (and the algorithm) are actually hearing 95 bpm (or 180 bpm). I’m assuming this is because musicians don’t always follow the exact tempo on the sheet music. Or that whoever transposed to the piano sheet music I’m looking at was listening to a slightly different recording. But it may be because I’m counting slightly off. In any case, it wouldn’t materially change what one would dance to it, so I’m going to leave this little nitpick at that.

And the list goes on:

When You’re Smiling by Michael Buble – A very Slow Foxtrot at 76 BPM or a Quickstep at 151 BPM.

Old Black Magic (the Oscar Peterson version) – A Slow Foxtrot at 104 BPM or a fast Quickstep at 209 BPM.

Why should you care?

As a DJ, these songs are great because dancers who may be comfortable with different dances can dance to the same song, and you’ve got a better chance of filling the dance floor. As a dancer, I’ve always found it fun to dance a fast swing in the middle of the floor while most of the room is dancing a Slow Foxtrot around the perimeter – but that may just be because I’m more comfortable with Swing than Foxtrot.

In addition, spending some time listening to these kinds of nuances is one way (certainly not the only way) to improve your musicality as a dancer.

Finally, I like picking at the edges of these kinds of things, and it is helping me focus a bit on cleaning up the catalog, since there is a strong overlap between these fun rhythms and the places where the algorithmic tempos don’t line up with the dance. So if that is the only real reason for this series, please bear with me, and feel free to skip them – hopefully the end result is a more accurate set of tempo/dance alignments than we had before.

Step of the Month

The “Step of the Month” for August:  This is a small variation on the July Step. Please share an unusual rhythm song (or songs) that you enjoy dancing to. I’m specifically looking for interesting variations that I haven’t mentioned yet in this series. I’ve got one more up my sleeve, but I’d like to continue on this path for more than three posts. But I need some help to do that. Post it in the comment thread here or send feedback.

Fun Rhythms: 12/8 meter- Slow Foxtrot + Viennese Waltz?

Since I’ve added the ability to set the tempo of a dance for a song independently of the tempo of the song itself, I’ve found some renewed energy to go through and clean up some of the inconsistencies that have crept into the music4dance catalog. As I promised (or threatened) when I blogged about the…

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Searching for Music

What dances work with the songs in a Spotify Playlist

Or: show me a Spotify playlist through the music4dance lens.

When I was writing the Jessic Lang/Tony Bennett post earlier this summer, I re-read the Twila Tharp/Frank Sinatra post from last year. I realized I’d written most of a music4dance feature for that post that I never completed or documented.

So I thought, this is some low-hanging fruit for a fun feature and blog post, so I’ll finish it up quickly and get a post out to show it to everyone. Famous last words. It turns out that the edge case that I implemented didn’t work for much more than the post that I created it for, and I had about 80% of the work left.

The Feature

I wanted to show the Nine Sinatra songs in the order they were performed in the context of music4dance. I could tag the songs with something unique and get a list of those songs as a music4dance search result. But that wouldn’t be in the same order as they are danced in the Ballet. So what should I do? I could write a full-fledged playlist feature, but that seemed like overkill, and I hesitate to do that, since then I’d have to maintain not only the code, but also the data for all the playlists people would be scrambling to create (sometimes I can be a bit of an optimist).

Or I could do something that I’ve been toying with for a while: take a Spotify playlist and show it as music4dance results, similar to any of the various searches you can already do on the site. Since I’m already integrated with the Spotify API, this was quite straightforward to implement. And, in short order, I was able to add a Nine Sinatra Songs Playlist link to the blog post that showed the songs in order with all the other information that I normally display for songs in the music4dance interface.

This worked fine because I created the playlist myself and made sure that all the songs were in the music4dance catalog. But what happens if some of them aren’t?

I decided to solve this by showing the Spotify tracks that I could match to music4dance songs first, then, for signed-in users, I’d follow that with a list of tracks that I couldn’t find, along with an “add” button. That way, anyone really interested in a playlist can add the songs that are missing (along with their preferred dance for each, of course).

That worked well, but then I realized that some of the songs that weren’t matched in the playlist were actually in the music4dance catalog. This is because any given Spotify track can have many Spotify IDs. I am keeping the ID that I found when I first looked up the song, but that might not be the same one that is referenced in the playlist. I will not go into the details, but after a couple of tries, I believe I have a solution that works around that issue – this took more time than the rest of the feature, but also addressed a long-standing issue with adding Spotify songs by ID.

So now you can drag a Spotify playlist onto the main search control in the upper right of the music4dance site (or the search control in the main menu for smaller screens).

Here are a couple of examples.

Jennifer Lopez Mix

This Is Billy Joel

This feature is available to everyone, but I’m trying to encourage folks to participate more in music4dance, so there is a limit on the number of songs you can see as an anonymous user, and the limit increases if you create an account and then some more if you subscribe.

Constraints and limitations

Even with my changes to improve looking up songs, that doesn’t get past the fact that the music4dance catalog contains a very small subset of the songs available on Spotify (and always will), so arbitrary playlists will generally not be complete.

This feature will only work for public playlists. I’m also not entirely sure that the way I’m accessing playlists will work for all public playlists. For instance, does it work for “Made for you by Spotify” playlists, where the you in that sentence isn’t me? Or an account associated with mine? I don’t really have access to that to test, so let me know what does and doesn’t work for you.

Moving forward

There are a couple of things that I didn’t implement (that I’m aware of). I’m trying to get features out and see what the community reaction is before investing too much time in new features. For this one, here are a few improvements I’d think about doing if people are using this feature regularly.

  1. The lookup is pretty slow, especially with a large playlist, since I’m matching each track individually and the only feedback you get is whatever the page loading feedback is for your browser. If there is positive feedback on the feature overall, I’ll figure out how to either speed it up or give better progress feedback (or both).
  2. I realized as I was testing this feature that it would also be interesting to provide this functionality for an album, which shouldn’t be too hard.
  3. There isn’t an obvious UX for showing that this is possible at all. The only way you would know that you could look at a Spotify Playlist through music4dance is to read this post. I’m not even sure where I’d put it in the documentation. If anyone has an idea for that, please let me know.

And, of course, if you have ideas that I haven’t thought of, please let me know that, too.

Step of the Month

The “Step of the Month” for July:  Please share an unusual rhythm song (or songs) that you enjoy dancing to. It doesn’t have to be a variation on 12/8 or in any way related to the discussion from my previous post, just something that’s a little different that you enjoy. Post it in the comment thread here or send feedback.

Nine Sinatra Songs – Ballroom inspired Ballet

Pacific Northwest Ballet included Twila Tharp’s Nine Sinatra Songs as part of their Director’s Choice performance this year. I’m not in any way qualified to review a Ballet performance, but I can say that I thoroughly enjoyed it and had a great time playing with the Ballroom-inspired aspects of the dancing as I watched the…

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Jessica Lang’s ZigZag – Ballet and Bennett

Pacific Northwest Ballet included Jessica Lang’s ZigZag in their All Lang performance this year. While it’s not as directly Ballroom-related as last year’s performance of Nine Sinatra Songs, it was a ballet danced to and inspired by Tony Bennett songs. And similar to Sinatra, Bennett’s songs are often well-suited to Ballroom dances, especially Swing and…

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Music and Dance

Fun Rhythms: 12/8 meter- Slow Foxtrot + Viennese Waltz?

Since I’ve added the ability to set the tempo of a dance for a song independently of the tempo of the song itself, I’ve found some renewed energy to go through and clean up some of the inconsistencies that have crept into the music4dance catalog. As I promised (or threatened) when I blogged about the update, I am going to share some of the fun rhythms I find in this process.

12/8 Meter

The first “fun rhythm” I’d like to talk about is the different rhythms a dancer may hear in music written in 12/8. This is effectively 4/4 time where each beat of 4/4 is a triplet, although technically it’s twelve eighth notes per measure (4 *3 = 12).

12/8 musical notation example
My quick demo of what 12/8 looks like on the page.

This post on Jade Bultitude’s site does a much better job of explaining and illustrating the musical part of this than I do.

Dancing to 12/8

The fun thing about this meter is that as a dancer you can count it in two ways – either as a 3/4 measure for each of the triplets or as 4/4 where you hear each triplet as a beat.  Then the triplet rhythm will sometimes work for a Viennese Waltz, and the 4/4 rhythm will work for a slow dance like a Slow Foxtrot, Nightclub Two Step, or Blues. Also note that if you’re looking at the sheet music for a song, you’ll generally see a dotted quarter-note as the measure of tempo, which means a musician is counting the tempo at four beats to a measure, effectively the same as 4/4,

Examples

“Like I’m Gonna Lose You” by Megan Trainor featuring John Legend is listed as West Coast Swing, Castle Foxtrot (e.g. Slow Dance), and Blues at 72 BPM, and Viennese Waltz and Tango Vals at 216 BPM on music4dance. The sheet music shows the tempo as 72 BPM, so I’ve set the main song tempo to that.

The sheet music for “Me and Mrs. Jones” by Michael Buble shows that it is technically in 6/8, but the same principle applies. The music4dance page shows votes for Viennese Waltz at 198.2 BPM and Castle Foxtrot (e.g. Slow Dance) and Slow Foxtrot at 66 BPM (this would be very slow for Slow Foxtrot).

Cataloging

I am still playing with how to tag these kinds of songs. Should I add a 12/8 tempo tag to the songs (*even if they might be technically 6/8 or 4/4 with strong triplets)? Should I put a 3/4 tag on the Waltzes and 4/4 on the Foxtrots, or is that redundant? Would it make sense to put a Compound Time tempo tag on all of these?

Next Steps

I’m going to continue to muddle through manually cleaning up these songs, but it will take some time, since there are a lot of these (and I haven’t even gotten into some of the other fun variations).

If you’re interested in seeing more examples and/or jumping in and cleaning them up, here are a few interesting music4dance searches:

If you are interested in helping, but find the documentation (or the discussion above) too confusing, or if you have thoughts on how to better tag these kinds of songs, please feel free to reach out with questions or comments.

Step of the Month

The “Step of the Month” for July:  Please share an unusual rhythm song (or songs) that you enjoy dancing to. It doesn’t have to be a variation on 12/8 or in any way related to the discussion above, just something that’s a little different that you enjoy. Post it in the comment thread here or send feedback.

Update – July 15th, 2026

An astute reader pointed out that I was conflating the terms meter and rhythm. I believe I’ve cleaned this up in the post; the general idea is that dancers hear and dance to a rhythm, while the time signature or meter is a technical term that is used in written music. I am still going to keep the title of this series as “Fun Rhythms”, since I am using this as a forum to talk about the way some dancers may hear the rhythms in a piece of music differently than others.

What Happens When a Song is Danced at Different Tempos?

Sometimes, a song can be a perfectly good Bolero when heard one way but a Salsa when counting the music differently. Another example is Slow Dance (Castle Foxtrot) vs. Lindy Hop. Generally, this phenomenon is because, with some music, it’s easy to count what the musicians see as either a half note or a quarter…

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Playing with Dance Tempos

I just rewrote the Tempo tool for the music4dance site as part of the current effort to update the site.  In the process I went back and revisited the reasons for writing the tool in the first place.  The main reason for this tool is to have a single place to do a bit of…

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Song Details

The music4dance song details page contains all of the information that we have gathered about a song, including tags and dances that you may have added. Below is a snapshot of a song details page for “How Sweet it Is” as seen by a user, “Charles”, while he is viewing it. Some of the features…

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Music and Dance

New Feature: Tempo-per-dance, or what if I want to Salsa to this song twice as fast as someone else wants to Cha Cha to it?

1 Comment

One of the things I’ve been struggling with since very early on in the music4dance story is the fact that not everyone hears the same rhythm when they dance to the same song. Struggling isn’t the right word – it’s a difficult technical problem to solve in the context of the music4dance song index, but a delightful result of the plurality of both music and dance (and musicians and dancers) that I celebrate.

In any case, I believe I’ve finally arrived at a reasonable solution, and it’s up and running on the site. You can now specify that a song is danced at 180bpm for Lindy Hop without trouncing on another dancer’s opinion that it should be danced at 95bpm for Night Club Two Step. And, most importantly, you can filter on Night Club Two Steps between 90 and 95bpm in advanced search, and that song will be included. And a search for Lindy Hops between 175 and 180 bpm will also include our hypothetical song.

I almost stalled out while writing this post because there are so many variations in tempo-per-dance. It’s a rabbit hole I could fall down and not emerge from for a very long time. I clawed my way out of that particular hole by promising myself that I would take time to write a series of posts, each one concentrating on one of the variations. We’ll see how that goes.

Bam Bam

And just to give a concrete example, “Bam Bam” by Camila Cabello was one of the songs that got me over the hump to implement this feature. A couple of sources listed this song as Salsa at 190 bpm, but one of the DJs who contributes to music4dance emailed me to let me know that he has been playing it at his dances as a Cha Cha, where folks dance to it at 95 bpm. And since he is a thorough researcher, he looked it up, and it’s listed at 95 bpm on the official sheet music. So, for a while, I had this song listed at 95 bpm for both Salsa and Cha Cha. But now it is one of the first songs I have corrected to use different tempos for different dances:

Screenshot of “Bam Bam,” showing Salas @ 190 and Cha Cha @ 95bpm
Screenshot of “Bam Bam,” showing Salas @ 190 and Cha Cha @ 95bpm
Salsa search for tempo @190bpm shows “Bam Bam.”
Salsa search for tempo @ 190 bpm shows “Bam Bam.”
Cha Cha search for tempo @95bpm also shows “Bam Bam.”
Cha Cha search for tempo @ 95 bpm also shows “Bam Bam.”

Where to go from here?

I’m spending some time tracking down the songs that are the most egregious offenders that can be corrected with this improvement. That includes things like the 4/4 songs that are half-time/double time of each other. Along these lines, I’ll probably implement more tempo constraints for dances to help me find such offenders – see “Ask music4dance: Why are the tempos that music4dance lists for Salsa wrong?” for more info. If you have thoughts on these kinds of tempo constraints, please let me know.

I’ll also be taking another look at Waltzes that are either marked as 4/4 or danced to other types of dances, since this is generally another flag that something funny is going on with rhythms and tempos.

Are there other places that you’ve noticed tempo listings conflicting with your expectations based on the dances you know well? If so, please take a run at fixing them up – I’ve moved to enabling more community modifications of these attributes, so with this change and updated documentation, hopefully you can fix things that look wrong to you – if not, I’d like to know so that I can improve the feature.

Step of the Month

The “Step of the Month” for June is to check your account management page. It is nice to see the songs another user has tagged. This information is available only to other logged-in members of the community, so please consider making your information available to the community by checking the “Share my Profile” option to improve other members’ experience (the alternative is that your votes and tags are attributed to an anonymous user, which is much less friendly).

What Happens When a Song is Danced at Different Tempos?

Sometimes, a song can be a perfectly good Bolero when heard one way but a Salsa when counting the music differently. Another example is Slow Dance (Castle Foxtrot) vs. Lindy Hop. Generally, this phenomenon is because, with some music, it’s easy to count what the musicians see as either a half note or a quarter…

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Enhanced Feature: Editing Tempos and Deleting Tags

Based on some of the comments on my last post, I’ve been thinking more about my early decisions concerning who can edit various aspects of a song in the music4dance catalog. I was worried that malicious actors would mess with the data, and spent considerable time designing and implementing a system that lets me roll…

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What is a fake Waltz?

I was recently asked why there are songs tagged as Waltz in the music4dance catalog that are in 4/4 time.  This seems almost like the dance version of an oxymoron.   In my brief description of the Waltz on the website I start with “Waltzes are dances that are danced to music in 3/4 time…” To…

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Ask music4dance: Why are the tempos that music4dance lists for Salsa wrong?

I’ve addressed questions about tempo in several different ways over the years, and I appreciate the continued feedback, as there is absolutely room for improvement in how the music4dance system handles tempo. Algorithms are far from perfect: The issue at hand is that many of the tempos listed for Salsa were exactly half the speed…

msc4dnc's avatar by msc4dnc