1.Functional Harmony 2.Circle Of Fifths 3.Cadential Expansion 4.Bassline-Driven Harmony 5.Modal Harmony 6.Modal Interchange 7.Secondary Dominants 8.Pedal Points 9.Common-Tone Harmony 10.Sequence-Based Harmony 11.Parallel Harmony 12.Ostinato-Based Harmony 13.Neo-Riemannian / Parsimonious Harmony 14.Chromatic Mediants 15.Tritone Substitution 16.Negative Harmony 17.Constant Structure Harmony 18.Symmetrical Harmony
Lesson 15

Tritone Substitution

Swap a dominant chord for one a tritone away to get smoother chromatic motion.

By the end: You can replace a dominant seventh with its tritone substitute and explain how their guide tones resolve to the tonic.

A tritone substitution replaces a dominant seventh chord with another dominant seventh whose root is a tritone away. In C, G7 can be replaced by D-flat 7 before the tonic.

G7 and D-flat 7 share the same tritone guide tones (B and F, with enharmonic spelling). Those notes still resolve into C and E, while the substitute bass can slide down by semitone into C.

Compare the dominant chords

Compare Dm7 – G7 – C with Dm7 – Db7 – C.

Try it

  1. Find a dominant seventh that resolves to your tonic.
  2. Move its root by six semitones and build another dominant seventh.
  3. Keep the target chord, then compare the bass movement and guide-tone resolution.

Key takeaway

The substitute keeps dominant function through shared guide tones while giving the bass a different, often smoother route to the tonic.