A♯9 Chord: Guitar, Piano and Notes
The A♯9 chord is a dominant ninth chord built on the root note A♯. Its notes are A♯, C𝄪, E♯, G♯ and B♯. It's enharmonically the same chord as B♭9.
Dominant ninth chords are a dominant seventh with extra shine. The ninth on top softens the bite of the tritone below it, which is why funk, soul and blues rhythm guitar lives on this chord.
- Notes
- A♯ · C𝄪 · E♯ · G♯ · B♯
- Formula
- 1 · 3 · 5 · ♭7 · 9
- Semitones
- 0 · 4 · 7 · 10 · 14
- Note
- A♯
- Quality
- Dominant 9
- Symbol
- A♯9
A♯9 on piano
5 notes
Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.
To play A♯9 on piano, place your right hand with your thumb on A♯, index finger on B♯, middle finger on C𝄪, ring finger on E♯ and little finger on G♯. Press the keys together and listen for an even sound. On the keyboard A♯ and G♯ are black keys and C𝄪, E♯ and B♯ are white, the keys you'd normally call D, F and C. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard. Practice moving in and out of the chord slowly, then bring in a metronome.
- A♯1
- B♯9
- C𝄪3
- E♯5
- G♯♭7
A♯9 on guitar
Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.
On guitar, A♯9 is commonly played with the voicing shown above. String 4 rings open. Don't play string 6.
A♯ · C𝄪 · E♯ · G♯ · B♯
Play A♯9 on the online piano
Free, in your browser: play with the mouse, your computer keyboard or a USB MIDI keyboard. No sign-up.
A♯9 chord notes
Also known as B♭9
| Degree | Interval | Semitones | Note | Hear |
|---|---|---|---|---|
| 1 | Root | 0 | A♯(A#) | |
| 3 | Major third | 4 | C𝄪(C##) | |
| 5 | Perfect fifth | 7 | E♯(E#) | |
| ♭7 | Minor seventh | 10 | G♯(G#) | |
| 9 | Major ninth | 14 | B♯(B#) |
How to use the A♯9 chord
The A♯9 chord is built from a root, a major third, a perfect fifth, a minor seventh and a major ninth. Start at the root A♯ and stack the intervals to get the whole chord: A♯, C𝄪, E♯, G♯ and B♯. The same formula gives you the chord in any other key.
Dominant ninth chords take the place of a plain dominant seventh in blues, funk, soul and jazz. As the V9 they resolve just like a V7 does, only with more colour on the way.
How A♯9 differs from similar chords
A♯9 is A♯7 with a major ninth on top, so it keeps the dominant pull of the tritone. It differs from A♯maj9 in the seventh, minor rather than major, and from A♯add9, which has no seventh at all. In A♯7♭9 and A♯7♯9 the same ninth is moved a half step down or up.
Where A♯9 is used
No progression is shown for this spelling
Every key A♯9 would have a function in has a tonic that needs a double accidental, which is not a key this library teaches. The enharmonic spelling carries the same chord in a key that exists.
Questions people ask
- What notes are in the A♯9 chord?
- The A♯9 chord contains A♯, C𝄪, E♯, G♯ and B♯ (A#, C##, E#, G# and B# in plain text).
- Is the A♯9 chord major or minor?
- A♯9 is a dominant ninth chord. Dominant ninth chords are a dominant seventh with extra shine. The ninth on top softens the bite of the tritone below it, which is why funk, soul and blues rhythm guitar lives on this chord.
- How do you play A♯9 on piano?
- Place your fingers on A♯, C𝄪, E♯, G♯ and B♯ and play them together. The root usually goes to the little finger of the left hand, the upper notes to the right. On the keyboard A♯ and G♯ are black keys and C𝄪, E♯ and B♯ are white, the keys you'd normally call D, F and C. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard.
- How do you play A♯9 on guitar?
- Use the fingering in the diagram above. String 4 rings open. Don't play string 6.
- What is another name for the A♯9 chord?
- A♯9 is enharmonically equivalent to B♭9. Both chord names describe exactly the same notes, but the spelling depends on the key you are playing in.