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.
Ebmaj7b5 is Eb, G, A and D — Ebmaj7 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.

| Eb | G | A | D |
|---|---|---|---|
| 1 | 3 | ♭5 | 7 |
Coloured tonic — rare, and unstable for a major chord.
Also written EbM7b5, EbΔ7b5 or Ebmaj7(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.
Ebmaj7b5 has 6 of them, on the top four strings, strings 5-3-2-1, strings 6-4-3-2, the bottom four strings and the middle four strings, from open position up to the 10th — all in one inversion, so the bass note never moves. The one to learn first is the Eb shape at the nut.
Start with xx1233 — no barre and down at the nut. None of the shapes for Ebmaj7b5 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 2 of the 6 need a barre. Together they cover the neck from the 1st fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| xx1233 | 1st fret | Eb, root position | G | all fretted |
| x65785 | 5th fret | Eb, root position | A | all fretted |
| x6778x | 6th fret | Eb, root position | G | all fretted |
| 11-10-12-12-10-10 | 10th fret | Eb, root position | D | barred |
| 11-12-12-12-x-11 | 11th fret | Eb, root position | Eb | barred |
| x-x-13-14-15-15 | 13th fret | Eb, root position | G | all fretted |
The same notes rebuilt from scratch give 14 drop 2, 9 drop 3 and 5 open string voicings, each on its own page.
Tensions. A shell of Ebmaj7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (F) and the 13 (C).
How you get to it. The turn that lands on Ebmaj7b5 is Fm7 to Bb7 — the ii and the V of Eb — and Bb7 shares its third and seventh with Fm7, so the hand barely moves between them.
In which keys. Every note of Ebmaj7b5 belongs to G minor (the ♭VI) and Bb major (the IV, the subdominant).
Every note of Ebmaj7b5 is in Eb lydian.
Change one note of Ebmaj7b5 and you have Ebmaj7 (the flat fifth becomes a fifth), Ebmaj7#5 (the flat fifth becomes a sharp fifth), EbmMaj7b5 (the major third becomes a minor third) or Eb7b5 (the major seventh becomes a flat seventh).
Ebmaj7b5 is a major chord — root, major third, fifth. Major chords on every root.
On Ebmaj7b5’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.