I agree with that every track is not for every emcee but I think that it doesn't have anything to do with it not being your own track. I rhyme over my own stuff all the time, and also over other producers beats, but it seems to me that there are just days that you wont feel certian beats and you cant do anything with them, then if you go back to that same beat a couple days or even a month later, it can turn out to be one of the best songs you ever made. For instance i got a friend who will always bring over his newest shit to show me and get feed back, there was a particular beat that i told him i didn't like, and i just wasn't feelin it. I always keep the cd's he gives me though....anyways about a month later i was lookin for some inspiration to write to and when that beat came on It caught my ear......We ended making a dope ass song to that same beat i hated in the beginning.......lol........and he never lets me live it down either....