How the key is worked out
WAVR looks at the strongest frequencies in each part of the track, from low bass up to about 2 kHz, and turns each one into a note. It first measures how far the whole track sits from standard A = 440 Hz tuning, so records pitched a few cents sharp or flat still read correctly. The notes are then folded into twelve pitch classes, C to B, giving a profile of which notes the track leans on.
That profile is compared with all 24 major and minor keys using two well-studied templates of how often each note appears in a key: the Krumhansl–Kessler listener ratings and Temperley's counts from a textbook corpus. The best match wins. WAVR also shows a confidence figure and the runner-up key, so you can tell a clear result from a close call.
Camelot and musical notation
Choose how keys are shown and written: Camelot (8A, 5B) for harmonic mixing, or musical (Am, Eb). Switching changes the tags on files you've already converted without re-encoding them.
The usual mix-ups
- Relative major and minor (A minor and C major) share every note. They also share a Camelot number, so the result still mixes well.
- Fifths (C and G): the fifth is the loudest overtone of many notes, so a bass-heavy track can pull one step around the wheel.
- Modal and atonal music: drones, Phrygian techno or noise don't fit major or minor cleanly, and confidence drops accordingly.
New to mixing by key? The guide to harmonic mixing with Camelot keys covers which keys blend and how pitch-shifting moves you around the wheel.
Key finder questions
What is Camelot notation?
The Camelot wheel numbers the 24 keys from 1 to 12, with A for minor and B for major. Keys with the same number, or one number apart, mix smoothly. A minor is 8A and C major is 8B.
Why did WAVR pick the relative major or minor?
A minor and C major use the same seven notes, which makes them the hardest pair to separate. They share the Camelot number, so they still mix well. WAVR lists the runner-up when it isn't sure.
Where is the key stored in the file?
As TKEY in MP3, WAV and AIFF, INITIALKEY in FLAC and OGG, and the iTunes initialkey field in M4A. Rekordbox, Serato, Traktor and Engine DJ read these.
Is my audio uploaded?
No. Detection runs in your browser. Nothing is sent anywhere.