Aadd#9 Major
The Aadd#9 chord is built from the notes A – C# – E – B#.
Piano sound loads on first tap.
Also known as
Aaltadd#9Amaj+9
Chord tones, one by one
ARoot
Root
The fundamental note the chord is built on — A.
C#Third
Major third
Four semitones — makes the chord major (brighter, happier).
EFifth
Perfect fifth
Seven semitones — the most stable interval, reinforces the root.
B#Extension
Sharp ninth (♯9)
A ♯9 — the gritty 'Hendrix' tension over a dominant chord.
🎼 Related scales
Lydian ♯2harmonic minor a major 3rd below
🎹 Modal analysis
This chord implies the Lydian ♯2 scale; its characteristic note is the ♯2 / ♯9 (augmented 2nd). It is a mode of the harmonic minor a major 3rd below.
🎸 Genres
Gypsy jazz · Roma music · Klezmer · Classical