BPM

The beat is the pulse you tap your foot to, and BPM counts how many of those pulses fit in a minute. One beat lasts 60 divided by the BPM, in seconds. At 120 BPM each beat is 0.5 seconds, a bar of four beats is 2 seconds, and an eight-bar loop is 16 seconds.

Rough tempos you will run into:

These ranges are loose, and the same number can feel different. A track at 140 BPM feels like 70 when the drums put the snare on beat 3 of each bar in place of beats 2 and 4. That is called a half-time feel.

To find a song’s BPM, count the beats for 15 seconds and multiply by 4, or use a tap-tempo button, which works out the tempo from how fast you tap. A metronome or click track plays the tempo back as a steady tick, so a take stays in time.

Tempo also sets the timing of effects. When the beat is a quarter note, as in most songs in 4/4, a quarter note lasts 60,000 divided by the BPM, in milliseconds. At 120 BPM a quarter-note delay is 500 ms and an eighth-note delay is 250 ms.

You set a BPM whenever you start a metronome, a drum machine, a looper or a DAW project. In Gelato Synth and Gelato Chord, the loop recorder starts with a tempo and a number of bars, and Gelato Chord adds tap tempo. Gelato Chord’s delay follows the tempo too: it repeats an eighth note later, 250 ms at 120 BPM. For a first beat at a set tempo, see how to make beats on iPhone.