Most of what I know about rap you could put on the front of a baseball cap*, so I'm looking forward to learning from your series But I do know this: Common's "Nag Champa" samples a wonderful prog duet from the Canterbury musicians Alan Gowen and Hugh Hopper:

https://youtu.be/pYS9eKtPUV0?si=uoHZ_V8sQvKlMx3F

* Just bought a Stillmatic cap at Goodwill the other day and listened to the album to see what I was missing. Jeez, what a genius.