How many semitones is a diminished twelfth?

A Diminished Twelfth spans 18 semitones: C – Gb. Count the semitones of any interval with the interval calculator.

Is a diminished twelfth the same as an augmented eleventh?

The same sound. The diminished twelfth resolves inward and the augmented eleventh outward, and the spelling declares which is meant.

What is a compound interval?

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

How do I play Diminished Twelfth?

On guitar the handiest shape is Next string, B 1 · E 14, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 18 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 Diminished Twelfth?

The inversion of Diminished Twelfth is the Tritone: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 18 semitones and 6 semitones, and swap their qualities between major and minor, or keep perfect as perfect.

Diminished 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 – Gb
C#	C# – G
D	D – Ab
Eb	Eb – Bbb
E	E – Bb
F	F – Cb
F#	F# – C
G	G – Db
Ab	Ab – Ebb
A	A – Eb
Bb	Bb – Fb
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. Diminished Twelfth spans 12 letter names, which makes it a twelfth, and 18 semitones, which makes it diminished.

DLetter
ELetter
FLetter
GLetter
ALetter
BLetter
CLetter
DLetter
ELetter
FLetter
18 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

Diminished Twelfth is in every chord whose formula includes 12d 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 LocrianC · Db · Eb · F · Gb · Ab · Bb
C Minor BluesC · Eb · F · Gb · G · Bb
C ChromaticC · Db · D · Eb · E · F · Gb · G · Ab · A · Bb · B

In C major

B–F

Related intervals

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

Tritone4A · 6 semitones · C – F#
Inversion: together they make an octave
Augmented Eleventh11A · 18 semitones · C – F#
The same sound, spelled differently
Diminished Fifth5d · 6 semitones · C – Gb
The simple form, an octave narrower
Perfect Eleventh11P · 17 semitones · C – F
One size away
Perfect Twelfth12P · 19 semitones · C – G
One size away

Open it in a tool

Understanding Diminished Twelfth

Names and symbols

Diminished Twelfth is written d12, 12d: 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 Diminished Twelfth spans 18 semitones: C – Gb. It is an octave plus a diminished 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 an augmented eleventh and is the compound form of the diminished fifth.

How it is used

It appears where a lowered fifth is voiced above the octave and its spelling has to follow the harmony.

Learn this properly

Chapter 5: Intervals

Common questions

How many semitones is a diminished twelfth?: A Diminished Twelfth spans 18 semitones: C – Gb. Count the semitones of any interval with the interval calculator.
Is a diminished twelfth the same as an augmented eleventh?: The same sound. The diminished twelfth resolves inward and the augmented eleventh outward, and the spelling declares which is meant.
What is a compound interval?: Any interval wider than an octave. A Diminished Twelfth is an octave plus a diminished fifth, and it keeps the character of that simple interval in a more open, less congested form.
How do I play Diminished Twelfth?: On guitar the handiest shape is Next string, B 1 · E 14, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 18 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 Diminished Twelfth?: The inversion of Diminished Twelfth is the Tritone: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 18 semitones and 6 semitones, and swap their qualities between major and minor, or keep perfect as perfect.