Bars per minute
BarsPM
Synonyms
BarsPM, Measures per minute, Bars per minute
Definition
Bars per minute. When we use this concept we can split the counting of beats with different time signatures in the same bar or measure. Instead of referring to the speed of the beats like it's done in the case of Beats per minute (BPM), we measure the speed of the bars, and we change the resolution of the beats or pulses for each one of the voices in a Polyrhythm. We don't do this using powers of 2 but using prime numbers instead.
Example
Split Polyrhythm
The speed of the Grammy is 120 BPM in quarter notes. If each bar encompasses 4 quarter notes, we can say that, in Bars, the speed of the Grammy is
- 120 / 4 = 30 Bars per minute (BarsPM).
A piece of music played in 5/4 at this same bar's speed would have a speed of
- 30 x 5 = 150 Beats per minute (BPM) in quarter notes.
If both voices (one in 4/4 and one in 5/4) where to play at the same time, this would be called a split polyrhythm. This means that the voices share the speed of the bar (BarsPM) but not the speed of the beat or pulse (BPM).
