Root position
A# – C## – E# – G#The root A# is the lowest note. This is the shape most people learn first.
4 notes · 1 · 3 · 5 · ♭7
A# Dominant Seventh Piano Chord (A#7)
A#7 is built from A#, C##, E# and G# — the formula 1 · 3 · 5 · ♭7, or 4, 7 and 10 semitones above A#. The shape uses 2 white and 2 black keys, and you can hear it, invert it and compare it below.
Chord
A# Dominant seventh
Notes
A# · D · F · G#Formula
1 · 3 · 5 · ♭7Right hand
1 · 2 · 3 · 5C
D
E
F
G
A
B
C
C#
D#
F#
G#
A#
Choose a chord, then play it. Finger numbers run from thumb (1) to little finger (5).
The finder above already holds A#7. Press P or the Play chord button to hear A#, C##, E#, G# sounded together, then change the root or the chord type to compare it with something else.
Chord tones
The notes in A#7
A dominant seventh chord is a major triad with a minor seventh added on top. The tritone between its third and its seventh is unstable and pulls strongly towards the chord a fifth below, which is what makes it the engine of blues, gospel and most cadences. In a major key it is built on the fifth degree.
| Note | Interval | Degree | Semitones | Right hand |
|---|---|---|---|---|
| A#black key | Root | 1 | 0 | 1 · thumb |
| C##white key | Major third | 3 | 4 | 2 · index finger |
| E#white key | Perfect fifth | 5 | 7 | 3 · middle finger |
| G#black key | Minor seventh | ♭7 | 10 | 5 · little finger |
Step by step
How to play A#7 on piano
- Find A#: it is the third black key in a group of three.
- Build upwards from A# using 4, 7 and 10 semitones to reach C##, E# and G#.
- With the right hand, place finger 1 on A#, finger 2 on C##, finger 3 on E# and finger 5 on G#. Keep the wrist level and the knuckles rounded.
- Move your hand a little further in towards the fallboard so the black keys sit comfortably under your fingers.
- Play the notes together, then one at a time from the bottom up, and listen to how A#7 settles.
- Try first inversion as well: C## – E# – G# – A#. Inversions let you change chords without jumping around the keyboard.
Inversions
A#7 in 4 positions
An inversion keeps the same 4 notes and simply moves the lowest one up an octave. Learning them means you can change chords with small hand movements instead of jumping to a new part of the keyboard.
First inversion
C## – E# – G# – A#C## is the lowest note, so the major third sits in the bass and the notes below it move up an octave.
Second inversion
E# – G# – A# – C##E# is the lowest note, so the perfect fifth sits in the bass and the notes below it move up an octave.
Third inversion
G# – A# – C## – E#G# is the lowest note, so the minor seventh sits in the bass and the notes below it move up an octave.
In context
Which keys contain A#7
In E♭ major the chord functions as V7. Altogether it is produced by the scales of 3 keys, so learning it once pays off in several places.
- E♭ majorV7
- C minorVII7
- E♭ harmonic minorV7
Chord tones are spelled by the degree they occupy, so the third of a minor chord is written as a flat rather than a sharp even though it is the same key on the piano. A double sharp such as F## means the key one whole tone above F.
Compare
A#7 against A#maj7
A#7 and A#maj7 share A#, C## and E#. Moving the major seventh G## down 1 semitone to the minor seventh G# turns A#maj7 into A#7.
Practise the pair together: hold the shared notes A#, C##, E# still and move only the one finger. Hearing that single change is the quickest way to recognise the two chords by ear.
Open A#maj7 →Good questions
A#7 questions
What notes are in the A#7 chord?
A#7 contains A#, C##, E# and G#. Counted from the root, that is the formula 1 · 3 · 5 · ♭7, or 4, 7 and 10 semitones above A#.
What is the right-hand fingering for A#7?
A comfortable beginner fingering is 1 (thumb) on A#, 2 (index finger) on C##, 3 (middle finger) on E# and 5 (little finger) on G#. Finger numbers run from the thumb (1) to the little finger (5), and they change once you start using inversions.
How is A#7 different from A#maj7?
A#7 and A#maj7 share A#, C## and E#. Moving the major seventh G## down 1 semitone to the minor seventh G# turns A#maj7 into A#7.
Which keys use the A#7 chord?
It occurs naturally in E♭ major (V7), C minor (VII7) and E♭ harmonic minor (V7). The roman numeral shows which degree of the key the chord is built on.
What are the inversions of A#7?
root position is A# – C## – E# – G#, first inversion is C## – E# – G# – A#, second inversion is E# – G# – A# – C## and third inversion is G# – A# – C## – E#. Every inversion holds the same notes; only the lowest one changes.
Is A#7 the same as the B♭ chord?
On an equal-tempered piano A# and B♭ are the same key, so the chords sound identical. Written music chooses between them according to the key signature: pages here are named after the sharp spelling of the root, and the chord tones are then spelled by the degree each one occupies, which is why a double sharp occasionally appears.