How many semitones is an augmented twelfth?

A Augmented Twelfth spans 20 semitones: C – G#. Count the semitones of any interval with the interval calculator.

Is an augmented twelfth the same as a minor thirteenth?

Identical in sound. The augmented twelfth resolves upward, the minor thirteenth downward.

What is a compound interval?

Any interval wider than an octave. A Augmented Twelfth is an octave plus an augmented fifth, and it keeps the character of that simple interval in a more open, less congested form.

How do I play Augmented Twelfth?

On guitar the handiest shape is Two strings up, A 3 · G 13, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 20 semitones up from any key, black keys included. Play the notes together for the harmonic form, one after the other for the melodic form.

What is the inversion of Augmented Twelfth?

The inversion of Augmented Twelfth is the Diminished Fourth: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 20 semitones and 4 semitones, and swap their qualities between major and minor, or keep perfect as perfect.

Augmented Twelfth Interval: How It Sounds, with Song Examples

Play it on your instrument

Loading the keyboard…

From

On the piano, from every note

From	Notes	Play it on your instrument
C	C – G#
C#	C# – G##
D	D – A#
Eb	Eb – B
E	E – B#
F	F – C#
F#	F# – C##
G	G – D#
Ab	Ab – E
A	A – E#
Bb	Bb – F#
B	B – F##

Tap a key or a fret to hear it.

Number and quality

An interval has two names. The number counts the letter names from the lower note to the upper one, and the quality counts the semitones inside that number. Augmented Twelfth spans 12 letter names, which makes it a twelfth, and 20 semitones, which makes it augmented.

DLetter
ELetter
FLetter
GLetter
ALetter
BLetter
CLetter
DLetter
ELetter
FLetter
20 semitones

Read on: number and quality · inversion · compound intervals · consonance and dissonance

Every twelfth

A twelfth can take these qualities, one semitone apart; choose one to see the upper note move and hear the pair.

Where it lives

Augmented Twelfth is in every chord whose formula includes 12A from the root, in every scale that includes it from the tonic, and between these pairs of notes in a major key.

Scales that contain it

C Whole ToneC · D · E · F# · G# · A#

Related intervals

The intervals one step from Augmented Twelfth: its inversion, the same sound spelled differently, its simple or compound form, and its nearest neighbours in size.

Diminished Fourth4d · 4 semitones · C – Fb
Inversion: together they make an octave
Minor Thirteenth13m · 20 semitones · C – Ab
The same sound, spelled differently
Augmented Fifth5A · 8 semitones · C – G#
The simple form, an octave narrower
Perfect Twelfth12P · 19 semitones · C – G
One size away
Major Thirteenth13M · 21 semitones · C – A
One size away

Open it in a tool

Understanding Augmented Twelfth

Names and symbols

Augmented Twelfth is written A12, 12A: the letter is the quality, the number the size. Chord formulas on this site write the number first, as tonal does.

A compound interval is a simple interval plus an octave, and the two names are used interchangeably in chord symbols: a 9th in a chord is the 2nd of the scale an octave up, an 11th the 4th, a 13th the 6th. The compound name says the note sits above the seventh.

How it sounds

A Augmented Twelfth spans 20 semitones: C – G#. It is an octave plus an augmented fifth, and compound intervals keep the quality of the simple interval inside them while losing much of its edge — the extra octave gives the two notes room to stop interfering with each other.

It measures the same as a minor thirteenth, and like the augmented fifth it tends upward rather than down.

How it is used

It is the compound form of the ♯5, met in altered dominant voicings spread across two octaves.

Learn this properly

Chapter 5: Intervals

Common questions

How many semitones is an augmented twelfth?: A Augmented Twelfth spans 20 semitones: C – G#. Count the semitones of any interval with the interval calculator.
Is an augmented twelfth the same as a minor thirteenth?: Identical in sound. The augmented twelfth resolves upward, the minor thirteenth downward.
What is a compound interval?: Any interval wider than an octave. A Augmented Twelfth is an octave plus an augmented fifth, and it keeps the character of that simple interval in a more open, less congested form.
How do I play Augmented Twelfth?: On guitar the handiest shape is Two strings up, A 3 · G 13, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 20 semitones up from any key, black keys included. Play the notes together for the harmonic form, one after the other for the melodic form.
What is the inversion of Augmented Twelfth?: The inversion of Augmented Twelfth is the Diminished Fourth: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 20 semitones and 4 semitones, and swap their qualities between major and minor, or keep perfect as perfect.