It sounds symmetrical and slightly unreal. The same four notes spell a 7♭5 a tritone away, which is exactly why one can stand in for the other.
5 moveable shapes, 2 of them drop 2. None has an open string in it, so each one plays every root there is; the dots are degrees, and R is the root.
Pick a root and every diagram below moves to it. Nothing about any of the grips changes — only the fret they start on, and each one starts somewhere different because they are rooted on different strings.
Showing C7♭5. Every voicing of it, open strings included, is on its own chord page.
No bass note under it, which is the point rather than a shortcoming: these sit above a bass player instead of competing with one, and they reach the extensions the lower shapes have no fingers left for.
x-x-10-11-11-12
4 notes · 3 frets
Same grip, also rooted on the G string
The same chord with something other than the root underneath. You reach for one of these because of what the bass is doing, not because of what the chord is — a bass line that walks while the harmony stays put is made of these.
3 in the bass.
3 on the D string, root on the B string
xx2312
4 notes · 3 frets
♭7 in the bass.
♭7 on the A string, root on the B string
x12312
5 notes · 3 frets
Close position — R–3–5–7 and its rotations — puts four notes inside an octave, which will not fit under a hand on adjacent strings. Drop the second voice from the top down an octave and it does. That is the whole operation, and it is why these exist: four notes, four adjacent strings, no gap to reach over, and the grip slides.
The base voicing only, one per string set. The same drop applied to the chord's other close voicings gives more grips, but those are inversions of a drop 2 rather than of the chord, and that is a distinction worth more than it costs to explain.
strings 6–5–4–3
♭5–R–3–♭7
2323xx
4 notes · 2 frets
strings 5–4–3–2
♭5–R–3–♭7
x-9-10-9-11-x
4 notes · 3 frets
Every voicing of one particular 7♭5 chord — including the open-string ones that do not move — is on that chord's own page, linked under each shape above. All the moveable shapes for every quality are on the shapes index, and the altered dominant chords as a family are on their own page.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.