A Diminished Piano Scale
Piano scale diagram
A Diminished Scale — Notes and Intervals
The A Diminished scale, also known as the Octatonic scale and Messiaen's Mode of Limited Transposition #2, alternates whole and half steps to create an 8-note symmetrical structure. On Piano, its notes are A, B, C, D, Eb, F, F#, G#. Only three unique diminished scales exist — after three transpositions, the notes repeat. It is the definitive sound of film noir, thrillers, and psychological horror, used by composers from Stravinsky to Hans Zimmer to evoke dread, ambiguity, and mounting tension. Use it over dim7 chords and as a sophisticated tension device over dominant 7ths. Commonly used in Jazz, Film Scores, Classical, Metal. Notable players include Django Reinhardt, Joe Pass, Bela Bartok, Dream Theater. Use over dim7 chords and as a tension device over dominant 7ths. Each diminished scale works over 4 different root notes (every minor 3rd).
Notes: A, B, C, D, Eb, F, F#, G#
Intervals: 1P, 2M, 3m, 4P, 5d, 6m, 6M, 7M
Degrees: 1 2 b3 4 5 b6 7 8
Formula: W-H-W-H-W-H-W-H
Number of notes: 8
Also known as: whole-half diminished
How to Play A Diminished on Piano
On piano, the A Diminished scale uses 3 black keys. Start with your thumb on A and use the black keys as landmarks for consistent finger placement. Standard major or minor fingering patterns apply.
The A Diminished scale contains both sharps and flats (2 sharps, 1 flat), which is common in altered and exotic scales. This scale does not follow a traditional major or minor key signature, so reading from sheet music may require accidentals.
Practice Routine
Begin by playing the A Diminished scale ascending and descending at 80 BPM using a metronome, one note per beat. Once comfortable, practice in thirds (A-C, B-D) to build intervallic familiarity. Spend 5 minutes daily on this pattern before increasing tempo by 10 BPM.
Experiment with simple two-chord vamps rooted on A to let the characteristic intervals of the Diminished scale come through clearly.
Piano Tips
At the piano, try voicing the A Diminished scale in the left hand as blocked intervals (thirds or sixths) while the right hand plays the melody. This develops your harmonic ear and comping skills simultaneously.
The A Diminished scale contains 8 notes (A, B, C, D, Eb, F, F#, G#). Use the interactive piano diagram above to explore this scale on Piano.