Intervals
Augmented Fifth
5A · 8 semitones
A fifth stretched by a semitone — the interval that makes an augmented triad hang in mid-air.
Also written A5 · 5A
Augmented Fifth
5A · 8 semitones
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.
Read on: number and quality · inversion · compound intervals · consonance and dissonance
Every fifth
A fifth can take these qualities, one semitone apart; choose one to see the upper note move and hear the pair.
Scales that contain it
C Whole ToneC · D · E · F# · G# · A#
Understanding Augmented Fifth
Names and symbols
Augmented Fifth is written A5, 5A: the letter is the quality, the number the size. Chord formulas on this site write the number first, as tonal does.
"Perfect" is not praise. Unisons, fourths, fifths and octaves take the qualities perfect, augmented and diminished, never major or minor, because their inversions keep the same quality. A fourth one semitone narrower than perfect is diminished, not minor.
How it sounds
An augmented fifth spans 8 semitones: C – G#. It sounds the same as a minor sixth, but it behaves differently: an augmented fifth wants to keep rising, a minor sixth to fall.
How composers use it
Stack two major thirds and the outer interval is an augmented fifth — the augmented triad, which divides the octave into three equal parts and therefore belongs to no key in particular. That symmetry makes it a smooth pivot between distant keys.
As an alteration on a dominant chord (the ♯5) it sharpens the pull toward resolution, and it is a staple of the jazz altered dominant.
Learn this properly
Chapter 10: Chords: Triads and SeventhsCommon questions
- How many semitones is an Augmented Fifth?
- An Augmented Fifth spans 8 semitones: C – G#. Count the semitones of any interval with the interval calculator.
- Is an augmented fifth the same as a minor sixth?
- Identical in sound, opposite in tendency. The augmented fifth resolves upward, the minor sixth downward, and the spelling declares which is intended.
- What chord is built on an augmented fifth?
- The augmented triad — root, major third, augmented fifth — two stacked major thirds that split the octave evenly.
- How do I play Augmented Fifth?
- On guitar the handiest shape is Next string, B 1 · E 4, read as string and fret; the instrument panel draws it from any starting note with the other shapes. On the piano count 8 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 Fifth?
- The inversion of Augmented Fifth 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, 8 semitones and 4 semitones, and swap their qualities between major and minor, or keep perfect as perfect.