"There are no sad or happy raps it seems to me but just angry ones" says Frank HGanmilton.

There are so - this one for example on a record by Four Men and a Dog called "Barking Mad.

I grant you that, insofar as it's an Irish folk band, it's not your typical rap, but I've heard happy rap often enough in the Notting Hill Carnival for example, though iot's not my music. "Sad rap" that isn't angry-sad - well I don't know about that. I suspect Frank might be rigfht there - but I don't know much about rap.