A# Diminished 7th

Notes:A# – C# – E – G
Formula:R-m3-d5-d7
Intervals:P1-m3-d5-d7
Scale Degrees:1-b3-b5-bb7

Introduction

The A# Diminished 7th piano chord (A#dim7) consists of the notes A#, C#, E, G. It is built by stacking three minor thirds, creating a fully symmetrical 4-note chord, giving it a extremely tense and dramatic character, fully symmetrical and harmonically versatile. Formula: R-m3-d5-d7 | Scale degrees: 1-b3-b5-bb7.

Enharmonic equivalent: A♯ is enharmonically equivalent to B♭. See Bb Diminished 7th.

Notes

Notes:A# – C# – E – G

A# Diminished 7th Inversions

PositionNotes
Root PositionA#4 – C#5 – E5 – G5
1st InversionC#5 – E5 – G5 – A#5
2nd InversionE5 – G5 – A#5 – C#6
3rd InversionA#4 – C#5 – E5 – G4

Key Signature

The key of A# Diminished 7th has Key signature data not available.

Theory: Intervals

Formula: R-m3-d5-d7
Intervals: P1-m3-d5-d7

The A# Diminished 7th is built by stacking intervals from the root note. The formula R-m3-d5-d7 describes the scale degrees used. The intervals P1-m3-d5-d7 show the distance between each note in the chord.

A# Diminished 7th — Frequently Asked Questions

What notes are in the A# Diminished 7th chord?

A# Diminished 7th is built from the A# root. Check the interactive keyboard above for exact notes and fingering.

How is the A# Diminished 7th chord used in music?

A# Diminished 7th appears in jazz, pop, and classical contexts. Its sound depends on the chord quality (Diminished 7th).

What is the fingering for A# Diminished 7th?

See the fingering chart above. Right hand typically uses thumb on root. Left hand uses pinky on root.

What are the inversions of A# Diminished 7th?

Use the inversion buttons above to see each inversion with notes, fingering, and staff notation.

Practice Tips

  • Symmetrical — only 3 unique dim7 chords.
  • Pivot chord for modulation.
  • Maximum dramatic tension.
  • Classical cadence chord.
  • Compare with A#m7b5.
  • Film scoring suspense.