A♯m(add9) — A♯, C♯, E♯, B♯ — is a minor add9 chord: minor triad + 9th (no 7th) — a brighter, more open colour than a plain minor triad without the full m9 stack.
Intervals
The A# minor add 9 chord stacks two thirds on the root. Each interval and its size in semitones:
- A#→C#minor 3rd3 semitones
- C#→E#major 3rd4 semitones
- E#→B#perfect 5th7 semitones
On the keyboard
Each note of the A# minor add 9 chord highlighted on a piano. Pitch class is what matters — any octave works.
On the guitar
One voicing of the A# minor add 9 chord on a six-string guitar fretboard.
- 1A#
- ♭3C#
- 5E#
- 9B#
Common mistakes
The defining note is the 9th (B♯). It sits more than an octave above the root, which is why the chord needs a wide voicing — in tight piano voicings the 9th usually appears in the top register while the root and lower triad tones cluster below.
In context
Functions as a brighter minor-tonic alternative; common in indie rock, ambient music, and modern jazz.
Drill it
The A# minor add 9 chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.
Open the Chord Trainer →Or try today's Etudle puzzleRelated
Frequently asked
- What notes are in a A♯m(add9) chord?
- A♯m(add9) contains four notes: A♯, C♯, E♯, B♯.
- How is A♯m(add9) different from A♯m7?
- A♯m(add9) adds the 9th (B♯) on top of the underlying 7th chord. The 9th extends the chord into the next octave and adds harmonic colour.
- When is A♯m(add9) used in music?
- Functions as a brighter minor-tonic alternative; common in indie rock, ambient music, and modern jazz.