Abbreviation for beats per minute, the common unit of tempo in music. The same symbol is used in medicine for heart rates and also for respiration rates (breaths per minute). Technically, 1 bpm is equal to 1/60 hertz
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}