A dim7 that shares its top note with the tonic chord — the harmony blurs and snaps back without the bass going anywhere meaningful. Decoration, not direction: pure sparkle on a held melody note.
hear it in barbershop tags · vintage Stevie intros
Lead-in — how players set it upDecorates a parked 1 — often under a held melody note.From 4, resolving plagally onto the shimmer's frame.Or under a melody note held from a previous 5⁷.Follow — where it usually goesSnaps back to 1; barbershop tags repeat it twice.Barbershop it — repeat the sparkle, then a real cadence.Or respell the dim7 and exit through one of its four doors.
Keep the common tone singing on top through the °7 — the shimmer is one still note over four leaning ones.Target tones (in C)C — lean on E (3)D#°7 — lean on F# (b3) · C (bb7)C — lean on E (3)Half-step wiresE ↘ D# · G ↘ F# · D# → E · F# → G