Scales & harmony from A
A theory reference for everything built on the tonic A: the diatonic chords of A major and A natural minor, the progressions they form, and the scale types that start from A.
Key relationships at a glance: the relative minor of A major is F# minor, and A minor shares its key signature with C major. Use the tables to compare harmony side by side, then jump to an instrument to hear the shapes under your fingers.