Key, Camelot code for DJ mixes, compatible keys and the exact tempo — in seconds.
Key and tempo are the first things you need to mix tracks, pick samples and record parts. For a DJ they tell which songs will blend without clashing. For a producer — what key to sing in or which loop to take so it sits with the harmony.
Getting it wrong is easy: few people can name a key confidently by ear, and file tags are often wrong or missing entirely.
The Camelot Wheel writes a key so that compatibility reads at a glance. Each key gets a code: a number from 1 to 12 plus A for minor or B for major. A minor is 8A, C major is 8B.
Compatible tracks share the same code, sit one number apart (±1), or share the number with the other letter. A move from 8A to 9A sounds smooth; 8A to 2A sounds harsh and out of tune. That is why DJ software shows Camelot rather than classical notation.
The key comes from a chromagram: the signal is split into twelve semitones and the accumulated profile is compared against reference profiles of every major and minor key using the Krumhansl–Schmuckler method. The best match wins.
Tempo comes from envelope autocorrelation: the algorithm looks for the period at which energy bursts repeat — the kick and snare hits.
Bought or downloaded a beat and need to know what key to write or record in? Upload it above — you'll get the note and Camelot code, making it easy to pick samples, melodies and harmonies that fit the beat. Works with MP3, WAV and FLAC.
Once your track on the beat is recorded and mixed — master it online: loudness for every platform, cleanup and final polish in one click.
Tracks that modulate — change key partway through — give an averaged answer: the algorithm reports the dominant key, not every one. The same goes for medleys and mixes.
Tempo sometimes reads double or half the real value: 140 instead of 70 BPM. That ambiguity is normal — signal-wise both are correct, so pick by how the beat feels. On material without a clear pulse (ambient, solo instrument) BPM may not resolve at all.