The mirror of the walk-ups: a dim7 fills the half step between 3- and 2-, so the bass glides 3, b3, 2 on its way to the 5⁷. Standard-issue in jazz ballads and gospel turnarounds.
hear it in jazz ballad turnarounds (3- to 2- lanes)
Lead-in — how players set it upReach 3- normally (often from 4), then start the descent.From 5/half-cadence energy, then the descent begins at 3-.Or from 6-⁷ — the lane extends one diatonic step higher.Follow — where it usually goes2- → 5⁷ → 1: the descent empties into the front door.Swap 5⁷ for the tritone sub: bass falls 2, b2, 1.Or turn around — climb back up through #2°⁷ to 3-.
Each passing °7 resolves DOWN here — let your line fall chromatically with the bass: 3, b3, 2.Target tones (in C)Em7 — lean on G (b3) · D (b7)Eb°7 — lean on Gb (b3) · C (bb7)Dm7 — lean on F (b3) · C (b7)G7 — lean on B (3) · F (b7)Half-step wiresE ↘ Eb · G ↘ Gb · Eb ↘ D · Gb ↘ F · C ↘ B