Every key, a fifth apart, arranged in a ring — the map that ties together key signatures, relative and parallel minors, and the chords of a key. Click a key to see its signature and its diatonic chords (colored by function: tonic, predominant, dominant), and play them. Moving one step clockwise adds a sharp; counter-clockwise adds a flat.
The three tonic, predominant, and dominant functions are the grammar of tonal harmony: predominants lead to dominants, dominants resolve to tonic.