Pick a root note and a scale to see what notes are in it and what chords are in the key. Every scale is spelled the way music theory writes it, so F major shows Bb rather than A#. You get the triads and seventh chords built on each note with roman numerals, the relative and parallel keys, the Camelot code DJs use for harmonic mixing, and a small keyboard that marks the notes. Click any chord to hear it and see it on the keyboard, or play the whole scale. It covers major and natural, harmonic and melodic minor, the modes from Dorian to Locrian, major and minor pentatonic and the blues scale. Free, with no sign in.
C major has C, Dm, Em, F, G, Am and Bdim, which are I, ii, iii, IV, V, vi and vii°. As seventh chords they are Cmaj7, Dm7, Em7, Fmaj7, G7, Am7 and Bm7b5. Pick any other key to see its chords the same way.
B natural minor is B, C#, D, E, F#, G and A. Its chords are Bm, C#dim, D, Em, F#m, G and A. Many songs in B minor also use F# major as the V chord, which comes from B harmonic minor; choose Harmonic Minor to see it.
D major is D, E, F#, G, A, B and C#, with two sharps. Its relative minor is B minor, and its Camelot code is 10B.
In a seven note scale each letter from A to G is used once. F major already has an A, so its fourth note is written Bb. The finder always spells scales this way, which is also how they appear in sheet music and key signatures.
They number the chords by the scale note they are built on. Upper case is a major chord, lower case is minor, ° is diminished, + is augmented and ø7 is half diminished. Because they describe the chord's place in the key, a progression like I V vi IV works in any key.
A relative key shares the same notes and key signature, like C major and A minor. A parallel key has the same root but the other mode, like C major and C minor. For modes such as D Dorian the finder shows the parent major key instead, here C major.
The Camelot wheel gives every key a number and a letter, A for minor and B for major, so A minor is 8A and C major is 8B. Keys one step apart on the wheel, or with the same number, usually mix well, and the finder lists them. To find the key of a recording, use Detect Key and BPM.
Yes. It is free, needs no sign in and runs in your browser. If you want MIDI parts written in a key you picked, MIDI Lab (midilab.ai) from the same team writes drums, bass, chords and melody from a prompt.