About Bmaj7b5 — drop 2 voicings
Bmaj7b5 is B, D#, F and A# — Bmaj7 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.
Bmaj7b5 notes and formula
| B | D# | F | A# |
|---|---|---|---|
| 1 | 3 | ♭5 | 7 |
Coloured tonic — rare, and unstable for a major chord.
Also written BM7b5, BΔ7b5 or Bmaj7(b5). The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Bmaj7b5
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.
Bmaj7b5 has 14 of them, on the bottom four strings, the top four strings and the middle four strings, from open position up to the 13th — every inversion the chord has: B in the bass, D# in the bass, F in the bass and A# in the bass. The one to learn first is the F shape at the nut, which is the easiest grip here.
5 of them sit on the bottom 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 x2334x — no barre and down at the nut. None of the shapes for Bmaj7b5 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 3 of the 6 need a barre. Together they cover the neck from the 1st fret to the 11th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x21341 | 1st fret | B, root position | F | all fretted |
| x2334x | 2nd fret | B, root position | D# | all fretted |
| 768866 | 6th fret | B, root position | A# | barred |
| 78880x | 7th fret | B, root position | D# | barred |
| 7888x7 | 7th fret | B, root position | B | barred |
| x-x-9-10-11-11 | 9th fret | B, root position | D# | 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 Bmaj7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (C#) and the 13 (G#).
How to use Bmaj7b5
How you get to it. The turn that lands on Bmaj7b5 is C#m7 to F#7 — the ii and the V of B — and F#7 shares its third and seventh with C#m7, so the hand barely moves between them.
In which keys. Every note of Bmaj7b5 belongs to Eb minor (the ♭VI) and F# major (the IV, the subdominant).
What to play over Bmaj7b5
Every note of Bmaj7b5 is in B lydian.
Chords near Bmaj7b5
Change one note of Bmaj7b5 and you have Bmaj7 (the flat fifth becomes a fifth), Bmaj7#5 (the flat fifth becomes a sharp fifth), BmMaj7b5 (the major third becomes a minor third) or B7b5 (the major seventh becomes a flat seventh).
Bmaj7b5 is a major chord — root, major third, fifth. Major chords on every root.
On Bmaj7b5’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.