For you Madlib fans, check out Stones Throw records (http://www.stonesthrow.com/
). It's run by Peanut Butter Wolf (a GREAT producer) and they're constantly putting out new stuff from Madlib and Oh No (Mad's cousin I think) plus a lot of other great djs and producers.
Regarding the arrangement/melody aspect of hip hop. One of the greatest beats from start to finish in my opinion is on Jay-Z's "Show Me What You Got". It was produced by Just Blaze (one of the all time greats) and is the first time Supertramp has ever let anyone use their music for sample purposes (and they still don't let anyone use their stuff). As a matter of fact, the song got leaked on the radio while they were trying to negotiate the use of the sample. The song blew up immediately, Supertramp threw a big fit, long story short Just Blaze had to pay out his backside so they could clear the song. It's a shame too, he didn't even leak the song, it was one of the cats working in his studio.
And so for your listening pleasure, "Show Me What You Got" live. Tony Royster's drumming on it, and completely merc'd the joint. As a matter of fact you see the Jigga just standing off to the side of the kit enamored with what Tony's doing. Definitely worth the watch, the drums come in pretty clearly, although the video is pix-elated.