109.173Happy Birthday modulation transition

Suppose first version is C.

Final version will be D♭.

At transition:

Option 1: hard cut after silence.

Option 2: A♭7→D♭.

Option 3: hold C as common/chromatic leading context? C can become maj7 of D♭, an especially interesting connection.

Sustain C.

Bass moves:

C→D♭.

Now C changes from:

tonic in C

to:

maj7 of D♭.

Beautiful reinterpretation.