A7(#9) chord
The A dominant seventh sharp ninth chord (abbreviated "A7(#9) chord") is a five-note chord consisting of the notes A, C♯, E, G, and B♯. The chord is formed by adding an augmented ninth to a A dominant seventh chord.
In practice, the fifth (E) is often omitted from the A7(#9) chord because it's not always possible to play all notes simultaneously.
Name
A dominant seventh sharp ninth chord
Synonym
A dominant sharp ninth chord
Notes
A C♯ E G B♯
Intervals
1 3 5 ♭7 ♯9
Chord symbol
A7(#9)
Alternative symbol
A7#9
Type
Pentad (five-note chord)