Free Song Key Finder

A song's key is the set of notes it is built on, plus the note that feels like home, called the tonic. A song in G major keeps returning to G, and most of its melody and chords use the seven notes of the G major scale.

Every key is either major or minor. Major keys tend to sound bright and settled; minor keys sound darker or more tense. The difference starts with the third note of the scale: in C major it is E, in C minor it is Eb.

Each major key has a relative minor that uses exactly the same seven notes but starts from a different tonic. C major and A minor share every note, as do G major and E minor. Because the notes are the same, a song can sit between the two, and relative keys always sound good together.

DJs mix in key so that two songs playing at once don't clash. The Camelot wheel below makes this quick: every key has a code from 1A to 12B, and keys with the same code, a number one step away, or the same number with the other letter blend smoothly. The detector shows the code next to the key and on each compatible key.

Singers check the key to see whether a song fits their range. If the chorus sits too high, moving the whole song down two or three semitones keeps its character and makes it comfortable to sing. The key tells you where you are starting from.

Songwriters and players work with the seven chords of the key. In a major key, the chords built on the first, fourth and fifth notes carry most songs, and the sixth adds a minor color. The result lists all seven chords and the notes of the scale, so you can write a melody, add harmony or jam along without working them out by ear.

The detector measures which notes the whole song uses most and compares that with the pattern of every major and minor key. That works for most songs, but some can read as a neighboring key instead.

Relative keys are the most common mix-up, because they share every note. A song in A minor that leans on its C major chords can come back as C major. If the result sounds wrong, try its relative key, shown right under it.

A key a fifth away is the next most likely result. It happens with songs that change key partway through, with modal songs that use the notes of one key but center on another, and with sparse arrangements such as a lone vocal or a few repeated chords. For a song that changes key, trim the file to one section and check each part on its own.