I’ve seen a number of questions recently about why information on the site is wrong.  So I’ll start with one of the easier ones, which I’ve seen a number of variations on but is basically, “why is the tempo wrong”.  Here’s the specific question that prompted me to write this post:

There are a lot of Ricky Martin songs where the beats/minute are twice what they should be (186 for “Casi un Bolero” ?!?!).

The quick answer is that this is wrong for a dancer – listening to this music, I would dance to it at 93 beats per minute rather than 186.  And the fact that people have voted for this song to be danced as Bolero (96-104bpm) or International Rumba (100-108bpm)  indicates that others would agree.

So why was this listed incorrectly?  Unlike other things on the music4dance site like which dance you would dance to a song, tempo at least of a particular recording of a song is not subjective.  And even amongst recordings of a song, there is generally not that much variation.  Sheet music generally has some kind of tempo marking which will tell musicians the tempo at which they should perform the music.  This can range from a general marking like Presto that indicates a range of about 168-200bpm to actual metronome markings of a precise bpm tempo.  Music Theory Academy has a great explanation of reading tempo markings if you would like to dig deeper.  But my main point is that there is generally a “right answer” to what the tempo is of a piece of music.

But if you notice the tempo that was listed for “Casi un Bolero” (186bpm) is exactly twice the tempo that we would dance to the music (93bpm).  Take a moment to listen to it (you can listen to a snippet on the “Casi Un Bolero” page on music4dance or the whole song on Spotify.com).  There are two instruments that are defining the beat – bass guitar and drum.  If we interpret this song as 4/4 at 93bpm, the bass guitar is emphasizing the first and third beats and playing occasional more complex phrases.  But you definitely hear a consistent one/three from that instrument.  on the other hand if you listen closely to the drum, it’s playing every eighth note (or 8 times each measure).  If you take the drum as the primary beat and definite that as a quarter note rather than an eighth note, you get a tempo of 186bmp.  Which is probably not what the musicians are thinking, and certainly not what a dancer is listening for.

Why is this important?  Because while many of the tempos listed on music4dance came from dancers who would hear the tempo that they can dance to a song, many other listings are generated via machine learning algorithms.  And the machine hasn’t quite figured out how to decide between listening to the bass or listening to the drums. In fact, both algorithms that I’ve used seem to prefer the drums.  So I occasionally go though and fix things up.  But with a catalog of nearly 40,000 songs and growing I’m not always keeping on top of that task.

As I rework the site, I’m hoping to get a moderation/curation function in to make it easy for others to help out with this.  So if you’re interested in helping out in that way, please let me know.  And as always I’m happy to hear from you with any kind of question, comment or feedback.

Quick Tip:

In this post I talk about the beats per minute of Bolero and International Rumba.  You can find listings of tempos for these and other dances in different forms on the tempi tool and competition ballroom page.