Cmaj9(#11) chord: major ninth sharp eleventh
Cmaj9(#11) is the major ninth sharp eleventh chord on C: C, E, G, B, D and F# (1–3–5–7–9–#11). Cmaj9(#11) stacks the root C, the major third E, the perfect fifth G, the major seventh B, the major ninth D and the augmented eleventh F#.
Notes in Cmaj9(#11): C – E – G – B – D – F#Formula: 1 – 3 – 5 – 7 – 9 – #11In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
Take a maj9 and add one unexpected note (F# over the C chord), and the sound takes on the floating shine of a film score. That color has a name: lydian. The note is raised on purpose, because the plain eleventh would rub against the major third in a semitone clash.
The same chord on all four instruments
Where to use it
Dreamy by nature, it opens or closes film-like ballads and modern jazz pieces. It is worth trying in place of a final maj7 when you want the music to end hanging in the air.
Part of the Extended family.