Tritone

Two major triads a tritone apart

Sorting the six notes into chords rather than steps makes the scale obvious: C E G is a C major triad, and G♭ B♭ D♭ is a G♭ major triad. Nothing else is in the scale, and nothing is left over.

Stravinsky used exactly that pair in Petrushka, which is why the sound has a name of its own outside theory books. Building the scale as two triads rather than as a row of intervals is also the fastest way to play it: two shapes already in the hands, a tritone apart.

The word means an interval far more often than a scale

Searching for tritone almost never lands on this scale. The overwhelming majority of the demand is for the interval — the augmented fourth, three whole tones, the gap between C and F♯ — and for tritone substitution, the reharmonisation trick where a dominant chord is replaced by another a tritone away.

Both are worth knowing and neither is this page. The interval is a distance between two notes; the substitution is a chord move; the tritone scale is a six-note collection. Adding the word scale to a search is what separates them.

The chord it sits on

Stacking from the root gives C E G B♭ — a dominant seventh — and the two remaining notes arrive as a flat ninth and a raised eleventh. Over C7 the scale is therefore a compact way to reach C7♭9♯11 without the extra colours a fuller scale would bring.

It is in fact a six-note subset of the half-whole diminished, which has eight. Dropping the sharp ninth and the thirteenth leaves exactly these notes, so a player who knows the diminished sound can hear this one as the same idea with less in it.

Symmetry at half an octave

The steps run half, minor third, whole, half, minor third, whole, and the second half repeats the first. Transposing the scale by six semitones therefore reproduces it exactly: C and G♭ tritone scales contain the same six notes.

One practical consequence follows. There are only six distinct tritone scales across all twelve roots, and any phrase can be moved half an octave and still belong — a property shared with the whole tone and diminished scales but with a different periodicity.

Everything else called tritone

The name is unusually crowded outside music. Tritone is an iPhone ringtone, a colour effect in video software, an audio plugin, and — from the Greek sea god — the name of Bernini's fountain in Rome, of a moon of Neptune under the spelling Triton, and of a synthesizer.

Two of these matter for search in particular. In Italian and Spanish the word is the ordinary name of the newt, the amphibian, which is why those markets return aquariums and species pages first; and in several markets a product line numbered 100 and 200 outranks every musical result.

Frequently asked questions