Returns harmonic substitution options for chord in the given key.
Covers: tritone substitution (for a dominant seventh), sus4 suspension (a dominant
seventh, or the major triad on V), deceptive resolution of V or V7 in major and minor
(to the key's triad on the sixth degree: vi in major, VI in minor; none in a mode),
diatonic substitutions in major and natural minor (a third away, same function:
I → iii, vi; ii ↔ IV; V ↔ vii°; i → III, VI), in minor keys V ↔ vii° and V7 ↔ vii°7
of the harmonic minor, and in major keys the minor subdominant family
(IV, ii → iv, bVII7, iiø7, and back to IV).
Returns harmonic substitution options for
chordin the given key.Covers: tritone substitution (for a dominant seventh), sus4 suspension (a dominant seventh, or the major triad on V), deceptive resolution of V or V7 in major and minor (to the key's triad on the sixth degree: vi in major, VI in minor; none in a mode), diatonic substitutions in major and natural minor (a third away, same function: I → iii, vi; ii ↔ IV; V ↔ vii°; i → III, VI), in minor keys V ↔ vii° and V7 ↔ vii°7 of the harmonic minor, and in major keys the minor subdominant family (IV, ii → iv, bVII7, iiø7, and back to IV).