A 7#11 Chord

How the A 7#11 chord is built: its notes, its interval structure, and where it fits.

The A 7#11 chord contains 4 notes: A – C# – D# – G. It belongs to the sharp 11 (lydian) family of chord qualities. Like every chord, it is defined by the distances (intervals) between its notes, not by any one instrument — which is why the same formula names the chord whether it is voiced on a fretboard, a keyboard, or a choir.