In
tonal music theory, a
diatonic function (also
chord area) is the specific, recognized role of each of the 7
notes and their
chords in relation to the
diatonic key. In this context,
role means the degree of tension produced by moving toward a note, chord or
scale other than the
tonic, and how this musical tension would be eased (
resolved) towards the stability of returning to the tonic chord, note, or scale (namely,
function).