83.105Apply it to “Mack the Knife”

For a later chorus:

keep melody recognizable.

Use walking bass as primary reharmonization engine.

At one phrase ending:

D-D♭-C-type bass approach.

At another:

borrowed inner-line darkening.

At modulation:

prepare new key through smooth semitone voice leading.

Because the tune already has strong theatrical identity, the reharmonization should support momentum rather than constantly announce itself.