BPM - What's behind it?
BPM = Beats per Minute. As a musician, it’s a rudimentary concept that applies to nearly every song written (John Cage may be a good exception). From introductory scales, to longhair classics to rap, BPM is an essential element.
Recently, I’ve been developing an app called Backtrack Cue. It’s intended for live bands that use backing tracks and/or a metromone click piped into their in-ear monitors. Typically, the drummer runs the backing track/click, launching either during a performance.
The app’s headline feature is quick BPM acquisition of a song. It can obtain a value in one of 3 ways:
- Retrieved from a public source (reccobeats.com) based on song title and artist
- Automatically analyzed through an in-app algorithm (for non-DRM* material)
- Manual tap-tempo function for DRM-protected songs
I have another app called StrideSync which plays songs based upon your walking, running, or indoor cycling cadence. It is entirely dependent upon BPM to function well.
There are some challenges in establishing BPM. They include:
- Different song versions can have different BPM values
- “Opinions” about BPM can vary, especially in public sources (Spotify, reccobeats.com)
- Automatic analysis can be wrong, sometimes doubling or halving the actual value
- BPM can vary with some songs, unintentionally or intentionally
In any case, if a band decides to perform a song at 110 BPM, even though the original varies throughout, it’s not a big deal - unless tempo variance is a deliberate song element.
I bring up this topic primarily as a navel-gazing exercise, and also to reflect on the methodology of my BPM acquisition design. I hope you find this interesting.
DRM = Digital Rights Management. Music streaming services (Spotify, Apple Music, etc.) use DRM to help prevent song piracy and artist’s rights. DRM-protected songs can be auditioned but not imported and altered by an application or utility.