About C#maj7b5 — drop 2 voicings
C#maj7b5 is C#, E#, G and B# — C#maj7 with the fifth lowered a semitone.
It sounds hollow and hard to place. Far more often met spelled the other way round, as a ♯11 over a chord that kept its fifth.
C#maj7b5 notes and formula
| C# | E# | G | B# |
|---|---|---|---|
| 1 | 3 | ♭5 | 7 |
Coloured tonic — rare, and unstable for a major chord.
Also written C#M7b5, C#Δ7b5 or C#maj7(b5). The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C#maj7b5
Take the four notes stacked as close together as they go, then drop the second voice from the top an octave. The gap it opens is what makes the chord sound like a chord rather than a cluster.
It lands on four adjacent strings, which is why it is the workhorse voicing on guitar.
C#maj7b5 has 13 of them, on the middle four strings, the bottom four strings and the top four strings, from the 2nd fret up to the 12th — every inversion the chord has: C# in the bass, E# in the bass, G in the bass and B# in the bass. The one to learn first is the B# shape at the 2nd fret, which is the easiest grip here.
5 of them sit on the middle four strings, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with x4556x — no barre and low, at the 4th fret. None of the shapes for C#maj7b5 uses an open string, so every one of them is movable; the lowest sits at the 3rd fret. 2 of the 5 need a barre. Together they cover the neck from the 3rd fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x43563 | 3rd fret | C#, root position | G | all fretted |
| x4556x | 4th fret | C#, root position | E# | all fretted |
| 9-8-10-10-8-8 | 8th fret | C#, root position | B# | barred |
| 9-10-10-10-x-9 | 9th fret | C#, root position | C# | barred |
| x-x-11-12-13-13 | 11th fret | C#, root position | E# | all fretted |
The same notes rebuilt from scratch give 5 shell and 9 drop 3 voicings, each on its own page.
Tensions. A shell of C#maj7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (D#) and the 13 (A#).
How to use C#maj7b5
How you get to it. The turn that lands on C#maj7b5 is D#m7 to G#7 — the ii and the V of C# — and G#7 shares its third and seventh with D#m7, so the hand barely moves between them.
In which keys. Every note of C#maj7b5 belongs to F minor (the ♭VI) and Ab major (the IV, the subdominant).
What to play over C#maj7b5
Every note of C#maj7b5 is in C# lydian.
Chords near C#maj7b5
Change one note of C#maj7b5 and you have C#maj7 (the flat fifth becomes a fifth), C#maj7#5 (the flat fifth becomes a sharp fifth), C#mMaj7b5 (the major third becomes a minor third) or C#7b5 (the major seventh becomes a flat seventh).
C#maj7b5 is a major chord — root, major third, fifth. Major chords on every root.
On C#maj7b5’s sound and use this page follows Robert Rawlins & Nor Eddine Bahha, Jazzology (Hal Leonard, 2005). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.