if u have any album credits, it should be in there.

But you can tell when it's Jay Dee vs. Q-Tip.

Example...Busta Rhymes album "The Coming"

Ill Vibe - clearly Q-Tip http://www.youtube.com/watch?v=RAlptXLnO9c
Still Shining - clearly Dilla http://www.youtube.com/watch?v=j8I1fwd9WWI
Ill Vibe remix - clearly Dilla http://www.youtube.com/watch?v=CCiBIXoefk8

most of that ummah shit was Dilla tho. lol