I’ll Remember April
There’s a good discussion about chord subs on this tune on website all about jazz, including this contrefact (new melody) by Miles on A section. Playing Gm+5 in bars 5 and 7 is worth exploring. I’ll send out a pdf of Miles’ solo, and you may want to check out some of these:
Ronnie Cuber (bari, Eb)
Marcus Printup (tr, C and Bb)
Clifford Brown (tr, C) and solo analysis