Here's a lead sheet for "I Remember you", a Jazz standard.

THere's a tag at the end of the melody that raises the key a minor 3rd before returning to the original key.
What I have done here is accept that modulation as a new key, so poart 2 is a minor 3rd highere. Then again and again, describing a diminished 7thchord.

The melody is done with really NO rhythmic indication, as is often the case with older Jazz Standards.
I am considering re-doing it in a rhythmic fashion, but here's a start.

There are changes for all 4 keys.

I would recommend raising the whole thing up a semitone and then again a semitone, and learning it in all these forms. Thois would take you through all 12 keys. There's a lot to learn doing this.

Best regards and Season's Greetings to all.