What is the tritone interval?
The tritone spans six semitones, landing exactly halfway between a note and its octave. Written upward it appears as an augmented fourth (C to F♯); written downward it becomes a diminished fifth (B to F). Because it refuses to settle like a perfect fifth, composers reach for the tritone whenever they need instant tension, ambiguity, or a sense of dramatic suspension.
Theory at a glance
In tonal harmony the tritone is a dissonance that almost begs for resolution. Traditional voice leading nudges the upper note up a semitone and the lower note down a semitone, collapsing the interval into a consonant third. This contrary motion powers every dominant seventh chord you build from the C Major scale. Stack E (the third) and B♭ (the seventh) over a G bass and you get the defining tritone of a G7 chord. Shift both notes outward by semitone and you land smoothly on the tonic triad, C major.
- Semitone distance: six steps (0 → 6)
- Scale-degree names: ♯4 in major keys, ♭5 in minor keys
- Enharmonic spellings: augmented fourth or diminished fifth
How it sounds
The tritone feels weightless and unsettled, which is why early theorists nicknamed it diabolus in musica. Train your ear with well-known references: the opening word “Ma—” in Maria from West Side Story, the first two notes of the The Simpsons theme, or the guitar riff of Jimi Hendrix's “Purple Haze”. Singing the interval against a sustained tonic or alternating it with a perfect fifth helps you feel the gravitational pull back to consonance.
Where you'll hear it
Dominant seventh chords, diminished sevenths, and tritone substitutions all showcase the interval. Jazz standards such as “Autumn Leaves” lean on the V7 to I cadence, while film composers stretch tritones over pedal points to build suspense before a dramatic release. You'll also find the interval baked into whole tone scales and the half–whole diminished scale, both of which pair tritones with symmetrical patterns.
Practice ideas
Map every tritone on the keyboard by pairing each white key with its partner six semitones away, then play them blocked and broken in both hands. Next, embed the sound inside dominant arpeggios—outline G7, then slide the upper voices down a semitone to hear the resolution into C major. Finally, improvise short phrases over a C Mixolydian vamp, deliberately leaning on the tritone before resolving it so your ear and hands internalise the motion.