Common substitution rules summarised. All examples transpose automatically with the key selector above.

Replace a dominant 7th chord with the dominant 7th whose root is a tritone (6 semitones) away. They share the same tritone (3rd and 7th swap roles), creating smooth chromatic voice leading into the tonic.

Replace a chord with another diatonic chord that shares two or more common tones. These substitutions stay within the key and are the gentlest way to add variety.

A dominant 7th chord borrowed from another key, used to temporarily tonicise any diatonic chord. The formula is: build a dominant 7th a perfect 5th above the target chord.

Chords taken from the parallel minor (or major) key to add colour and surprise within a major or minor progression. The ♭VII, ♭VI, and iv are especially common in rock and pop.

Two chords whose roots are a major or minor third apart and which share no diatonic relationship. They create striking, cinematic colour shifts used widely in film scoring and Neo-Riemannian voice leading.

Adding or altering extensions (7ths, 9ths, 11ths, 13ths) to enrich a chord or build tension before resolution.