Intervals
Tritone
4A · 6 semitones
Three whole tones — the most unstable interval in tonal music, and the engine that makes dominant chords resolve.
Also written A4 · 4A · TT
Tritone
4A · 6 semitones
On the piano, from every note
| From | Notes | Play it on your instrument |
|---|---|---|
| C | C – F# | |
| C# | C# – F## | |
| D | D – G# | |
| Eb | Eb – A | |
| E | E – A# | |
| F | F – B | |
| F# | F# – B# | |
| G | G – C# | |
| Ab | Ab – D | |
| A | A – D# | |
| Bb | Bb – E | |
| B | B – E# |
Tap a key or a fret to hear it.
Read on: number and quality · inversion · compound intervals · consonance and dissonance
Every fourth
A fourth can take these qualities, one semitone apart; choose one to see the upper note move and hear the pair.
Hear it in music
Songs that open with Tritone: the first two notes of each are the interval, which is how most players learn to recognise it.
The Simpsons ThemeDanny Elfman
The opening "The Simp-sons" leaps a tritone.
MariaLeonard Bernstein
The first two syllables of "Ma-ri-a" outline a tritone.
Purple HazeJimi Hendrix
The opening riff is built on one.
Scales that contain it
C LydianC · D · E · F# · G · A · B
C Whole ToneC · D · E · F# · G# · A#
C AlteredC · Db · D# · E · F# · Ab · Bb
C Lydian DominantC · D · E · F# · G · A · Bb
C Half-Whole DiminishedC · Db · Eb · E · F# · G · A · Bb
In C major
- F–B
Understanding Tritone
Names and symbols
Tritone is written A4, 4A, TT: the letter is the quality, the number the size. Chord formulas on this site write the number first, as tonal does.
"Tritone" names a sound, not a spelling: the augmented fourth and the diminished fifth are both six semitones and both go by the name. Which one is written depends on the letters — F to B is an augmented fourth, B to F a diminished fifth — and the spelling says where the line is going.
How it sounds
A tritone spans 6 semitones: C – F#. It splits the octave exactly in half, which makes it the only interval that inverts to itself: a tritone up and a tritone down land on the same pitch class.
Because it is perfectly symmetrical it has no gravity of its own, and that is precisely what makes it restless. It sounds like it must go somewhere without suggesting where.
How composers use it
The tritone between the third and seventh of a dominant seventh chord is what makes that chord want to resolve: the third rises, the seventh falls, and the two voices close inward onto the tonic. Remove it and the pull disappears.
Its symmetry is also the basis of tritone substitution: because D♭7 contains the same tritone as G7, it can stand in for it and resolve to C just as convincingly, with a chromatically descending bass.
Medieval theorists called it diabolus in musica — the devil in music — less as superstition than as a teaching rule about an interval that was hard to sing and harder to resolve.
Learn this properly
Chapter 5: IntervalsCommon questions
- How many semitones is a Tritone?
- A Tritone spans 6 semitones — exactly half an octave: C – F#. Count the semitones of any interval with the interval calculator.
- Why is the tritone called the devil in music?
- Medieval theorists flagged it as difficult to sing and unstable to resolve, and the nickname stuck. It was a pedagogical warning, not a prohibition.
- What is the inversion of a tritone?
- Another tritone. It is the only interval that inverts to itself, because it divides the octave exactly in half.
- How do I play Tritone?
- On guitar the handiest shape is Next string, B 1 · E 2, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 6 semitones up from any key, black keys included. Play the notes together for the harmonic form, one after the other for the melodic form.