How to Find the Key of a Song

Method 2: Work it out from the chords

If you know the chords, the key is usually the chord the song keeps coming home to — the one that feels like rest at the end of a phrase. Match the set of chords to a key's diatonic chords: a song using C, F, G, and Am is almost certainly in C major (or its relative, A minor). The final chord of the progression is a strong clue to which of the two it favours.

Method 3: Find the home note by ear

Play the song and hum the note it feels settled on — the one your voice drifts to when the music pauses. That tonic is the root of the key. To tell major from minor, listen to the mood: major sounds bright and resolved, minor sounds darker. Ear-finding is slower but it is the check that catches a wrong automatic reading.

How accurate is audio key detection?

Treat it as a strong estimate, not gospel. Tracks with simple, stable harmony read reliably; songs with frequent chord changes, key modulations, or heavy sound design can fool the algorithm — and it sometimes returns the relative major or minor instead of the one you hear. For a quick DJ set or a starting point it is plenty; for writing a part that has to sit perfectly in tune, confirm by ear after you see the result. Once you have the key, the Camelot code tells you which other tracks will mix with it.