Tritone Scale

The tritone scale (also called the two-semitone tritone scale) is a symmetrical hexatonic scale built around the tritone interval. It's less commonly encountered than the whole tone or diminished scales but has a distinctive tense, chromatic quality. The name comes from the scale's structure: two pairs of half steps separated by a tritone, giving it a symmetrical architecture that repeats at the tritone transposition.

Construction

C tritone scale:
C  D♭  D  F#  G  A♭  C

Step pattern: H - H - A2 - H - H - A2
(A2 = augmented second / minor third)

Formula: 1  ♭2  2  ♯4  5  ♭6

Six notes, symmetrical around the tritone (F#).

The scale divides into two identical groups of three notes, each group spanning a tritone: C-D♭-D and F#-G-A♭. Each group is two chromatic passing tones surrounding a target note, a tritone apart.

Symmetry

Like the whole tone and diminished scales, the tritone scale has limited transpositions due to its symmetry:

C tritone scale:  C D♭ D F# G A♭
F# tritone scale: F# G A♭ C D♭ D  (same notes)

Only six distinct tritone scales exist (one per pair of tritone-related pitches).

Sound and Character

Chromatic, tense, unsettled. The consecutive half steps create chromatic clusters, while the tritone gap creates instability. It doesn't suggest a clear harmonic context the way the whole tone scale suggests augmented dominants or the diminished scale suggests altered dominants. It's more of a texture than a harmonic tool.

Use

The tritone scale appears in contemporary classical composition and avant-garde jazz where symmetric scale patterns are explored. Over dominant seventh chords, the ♭9 and natural 2nd together with the tritone create an altered dominant colour similar to parts of the diminished scale. For most jazz improvisation applications, the half-whole diminished scale gives a more complete and harmonically grounded version of this chromatic-altered dominant sound. The tritone scale is niche — useful to know, rare in practice.