Tritone Interval

1Composition: what it contains

Semitones

6

Abbreviation

TT

Inversion

tritone

Consonance

dissonance

2Appearance: diagrams and sound

3Indications: what it is used for

The tritone between the third and seventh of a dominant seventh chord drives the V7–I resolution. It appears in diminished and half-diminished chords, in the Locrian and Lydian modes, in tritone substitution (replacing V7 with the dominant seventh a tritone away), and as the flat fifth of the blues scale. Metal and film music use it for menace; jazz uses it in ♯11 and ♭5 colours. Sirens and some alarm sounds use similar dissonant intervals.

4Dosage: how to practise it

On guitar, six frets on one string, or one fret higher on the next higher string (one fret further across the third and second strings). On piano, six half steps. Sing it by thinking of the raised fourth of the Lydian mode. Play a dominant seventh chord and isolate its third and seventh, then resolve them inward or outward. Train it daily with an ear trainer for three minutes, comparing with the perfect fourth and fifth.

Train it in the ear trainer

5Warnings and common mistakes

The same sound can be spelled as an augmented fourth (letters four apart) or a diminished fifth (letters five apart): choose the spelling according to the chord or scale. Inverting a tritone gives another tritone. Do not confuse it with the perfect fourth or fifth, which are half a step smaller or larger. Without context the ear cannot tell which note is the root.

6Other presentations available

• Perfect Unison Interval
• Minor Second Interval
• Major Second Interval
• Minor Third Interval
• Major Third Interval
• Perfect Fourth Interval
• Perfect Fifth Interval
• Minor Sixth Interval
• Major Sixth Interval
• Minor Seventh Interval
• Major Seventh Interval
• Perfect Octave Interval