Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top.
Dmaj7b5 is D, F#, Ab and C# — Dmaj7 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.

| D | F# | Ab | C# |
|---|---|---|---|
| 1 | 3 | ♭5 | 7 |
Coloured tonic — rare, and unstable for a major chord.
Also written DM7b5, DΔ7b5 or Dmaj7(b5). The same chord either way; which spelling you meet depends on who wrote the chart.
Root, third and seventh. The third and seventh, the guide tones, are what make the chord major, minor or dominant, so the fifth can go: it says nothing the symbol needs.
Three notes means a spare string, which is the real point. Put a tension on it.
Dmaj7b5 has 5 of them, on strings 5-3-2-1, the top four strings, strings 6-4-3-2, the bottom four strings and the middle four strings, from the 4th fret up to the 9th — all in one inversion, so the bass note never moves. The one to learn first is the D shape at the 4th fret.
Start with xx0122 — no barre and 1 open string. 1 of the 6 shapes here sits in open position. 2 of the 6 need a barre. Together they cover the neck from the 1st fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| xx0122 | open position | D, root position | F# | 1 open string |
| x54674 | 4th fret | D, root position | Ab | all fretted |
| x5667x | 5th fret | D, root position | F# | all fretted |
| 10-9-11-11-9-9 | 9th fret | D, root position | C# | barred |
| 10-11-11-11-x-10 | 10th fret | D, root position | D | barred |
| x-x-12-13-14-14 | 12th fret | D, root position | F# | all fretted |
The same notes rebuilt from scratch give 13 drop 2, 9 drop 3 and 3 open string voicings, each on its own page.
Tensions. A shell of Dmaj7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (E) and the 13 (B).
How you get to it. The turn that lands on Dmaj7b5 is Em7 to A7 — the ii and the V of D — and A7 shares its third and seventh with Em7, so the hand barely moves between them.
In which keys. Every note of Dmaj7b5 belongs to F# minor (the ♭VI) and A major (the IV, the subdominant).
Every note of Dmaj7b5 is in D lydian.
Change one note of Dmaj7b5 and you have Dmaj7 (the flat fifth becomes a fifth), Dmaj7#5 (the flat fifth becomes a sharp fifth), DmMaj7b5 (the major third becomes a minor third) or D7b5 (the major seventh becomes a flat seventh).
Dmaj7b5 is a major chord — root, major third, fifth. Major chords on every root.
On Dmaj7b5’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.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.