Classical · Jazz · FilmC → D / F / Ab / B · pick an exit
#1°7 → resolve up a half step from ANY tone
A dim7 is four stacked minor 3rds — perfectly symmetrical, so any of its four notes can act as the leading tone. Enter it in your key, respell it in your head, exit into whichever of the four keys you want.
hear it in Romantic-era modulations · silent-film scoring
Lead-in — how players set it upEnter the dim7 as a familiar passing chord off 1.Or arrive at the dim7 from above: 2-⁷ falling onto #1°⁷.Or spotlight it — fermata on the hinge, let the ear float.Follow — where it usually goesPick an exit, then cadence in that key like you meant it.Cadence hard wherever you exit — symmetry needs an anchor after.Or respell again mid-flight — two hinges reach every key alive.
Any °7 note can be a leading tone — pick ONE, hold it, resolve it up a half step, and the ear accepts whichever key you chose.Target tones (in C)C#°7 — lean on E (b3) · Bb (bb7)D — lean on F# (3)F — lean on A (3)Ab — lean on C (3)B — lean on D# (3)Half-step wiresC# → D · G ↘ F# · F# ↘ F · A ↘ Ab · C ↘ BAcross the borderno shared tonic tones with D — cut clean and re-land