Beats per minute

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Beats per minute (BPM) is a unit typically used as either a measure of tempo in music, or a measure of one's heart rate. A rate of 60 bpm means that one beat will occur every second. One bpm is equal to 1/60 Hz.

Beats per minute became common terminology in popular music during the disco era because of its usefulness to DJs, and remain important in dance music. Hip hop typically uses a BPM tempo of 70-110, while house music is faster: 110 -140BPM. Jungle music goes even faster: 140-190, while gabber tops it with above-200 BPM and Speedcore with upwards of 200 BPM. The Extratone subgenre regularly tops 1000 BPM. These values are general guides, however, and should not be interpreted as absolute.

Beatmixing, an art amongst DJs, concerns the speeding up or down of a record in order to match the BPM of a previous track so both can be flawlessly mixed. Normally, the pitch and BPM of a track are linked: spin a disc 10% faster and both pitch and tempo will be 10% higher. Software processing to change the pitch without changing the tempo, or vice-versa, is called time-stretching or pitch-shifting. While it works fairly well for small adjustments (± 20%), the result can be noisy and unmusical for larger changes.

BPM can be calculated by hand (count the number of downbeats/bass drums per 60 seconds, or - to be fast - per 15 seconds and multiply by 4), but some software programs such as MixMeister, Traktor-DJ and PC-DJ can do it automatically.