DJ tool
Key & tempo calculator
Change a track's speed without time-stretching and its pitch moves with it. This tool converts between the two: find the tempo that shifts a track to a target key, or find the key you land on when you change the tempo. It works the same whether the track is major or minor.
Change the key, find the tempo
Pick where the track sits now and where you want it. You get the speed-up and slow-down tempos that reach it.
Change the tempo, find the key
Pick the original key and tempo, then the new tempo. You get the resulting key and how far off it lands, in cents.
How does changing tempo change the key?
When you change speed without time-stretch, like on a turntable or a classic pitch fader, pitch and tempo are locked together. Each semitone up is a 5.95% speed increase, and each semitone down is a 5.61% decrease. A full octave, twelve semitones, doubles or halves the tempo. So a track that plays 5.95% faster also plays exactly one semitone higher.
This is why harmonic mixing and tempo matching pull against each other: nudging two tracks to the same BPM can drag one slightly out of key. The cents readout above tells you how far. Anything under about 20 cents is hard to hear; past that, a key lock or a real pitch shifter keeps the key while you move the tempo.
Make the tracks, not just mix them
Songen generates royalty-free loops in over 50 styles, the lead, chords, bass and drums as editable MIDI, so you can build your own edits and originals to drop in a set. Music generator for beat makers.