88.104Apply it to “Happy Birthday”

Because the melody is public domain, try three statements.

Statement 1

Simple C harmony.

Introduce one distinctive color only once:

perhaps Fm→C near an ending.

Statement 2

Do not use Fm.

But use A♭ briefly in an inner voice/melody decoration.

The ear may remember the earlier borrowed-minor color.

Statement 3

Return Fm→C at the final cadence.

Now it sounds like:

a callback,

not merely a substitution.

Then end on very simple C.

The final simplicity gains meaning from what preceded it.