How many semitones is a perfect twelfth?

A Perfect Twelfth spans 19 semitones: C – G. Count the semitones of any interval with the interval calculator.

Why does a clarinet overblow at the twelfth?

Its cylindrical, stopped bore suppresses even harmonics, so the first available overtone is the third — a perfect twelfth above the fundamental.

What is a compound interval?

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

How do I play Perfect Twelfth?

On guitar the handiest shape is Next string, B 1 · E 15, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 19 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 Perfect Twelfth?

The inversion of Perfect Twelfth is the Perfect Fourth: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 19 semitones and 5 semitones, and swap their qualities between major and minor, or keep perfect as perfect.

Perfect 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 – Bb
E	E – B
F	F – C
F#	F# – C#
G	G – D
Ab	Ab – Eb
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. Perfect Twelfth spans 12 letter names, which makes it a twelfth, and 19 semitones, which makes it perfect.

DLetter
ELetter
FLetter
GLetter
ALetter
BLetter
CLetter
DLetter
ELetter
FLetter
19 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

Perfect Twelfth is in every chord whose formula includes 12P 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 MajorC · D · E · F · G · A · B
C MinorC · D · Eb · F · G · Ab · Bb
C Harmonic MinorC · D · Eb · F · G · Ab · B
C Melodic MinorC · D · Eb · F · G · A · B
C DorianC · D · Eb · F · G · A · Bb
C PhrygianC · Db · Eb · F · G · Ab · Bb
C LydianC · D · E · F# · G · A · B
C MixolydianC · D · E · F · G · A · Bb
C Major PentatonicC · D · E · G · A
C Minor PentatonicC · Eb · F · G · Bb
C Minor BluesC · Eb · F · Gb · G · Bb
C Major BluesC · D · Eb · E · G · A
C ChromaticC · Db · D · Eb · E · F · Gb · G · Ab · A · Bb · B
C Phrygian DominantC · Db · E · F · G · Ab · Bb
C Harmonic MajorC · D · E · F · G · Ab · B
C Lydian DominantC · D · E · F# · G · A · Bb
C Half-Whole DiminishedC · Db · Eb · E · F# · G · A · Bb

In C major

C–G
D–A
E–B
F–C
G–D
A–E

Related intervals

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

Perfect Fourth4P · 5 semitones · C – F
Inversion: together they make an octave
Diminished Thirteenth13d · 19 semitones · C – Abb
The same sound, spelled differently
Perfect Fifth5P · 7 semitones · C – G
The simple form, an octave narrower
Minor Thirteenth13m · 20 semitones · C – Ab
One size away
Perfect Eleventh11P · 17 semitones · C – F
One size away

Open it in a tool

Understanding Perfect Twelfth

Names and symbols

Perfect Twelfth is written P12, 12P: 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 Perfect Twelfth spans 19 semitones: C – G. It is an octave plus a perfect 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.

The perfect fifth an octave up — a 3:1 ratio, which makes it the third harmonic and one of the most consonant intervals there is.

How it is used

It is the interval an organ quint stop adds, and the reason a clarinet overblows at the twelfth rather than the octave: its closed pipe suppresses the even harmonics.

Learn this properly

Chapter 5: Intervals

Common questions

How many semitones is a perfect twelfth?: A Perfect Twelfth spans 19 semitones: C – G. Count the semitones of any interval with the interval calculator.
Why does a clarinet overblow at the twelfth?: Its cylindrical, stopped bore suppresses even harmonics, so the first available overtone is the third — a perfect twelfth above the fundamental.
What is a compound interval?: Any interval wider than an octave. A Perfect Twelfth is an octave plus a perfect fifth, and it keeps the character of that simple interval in a more open, less congested form.
How do I play Perfect Twelfth?: On guitar the handiest shape is Next string, B 1 · E 15, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 19 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 Perfect Twelfth?: The inversion of Perfect Twelfth is the Perfect Fourth: put the lower note an octave higher and the distance that remains is the inversion. The two always add up to an octave, 19 semitones and 5 semitones, and swap their qualities between major and minor, or keep perfect as perfect.