Quincy Jones got added to songs he didn't write. Q was Arranger first and then a Producer.

however once he got his Yellow brick road publishing company he bought up stuff and also forced the deal to get credit, like how he muscles James Ingram to give up 50% of the fast version of PYT or not be included on thriller.

trip out thing about that song is the orignal was a slow jam composed by Michael Jackson and Greg Philiganis.

thing is credits also don't always tell the actual credit.

cats get a credit for flipping a word.

hip hop Producers who might sample make sure they get a credit because if said act they sample from takes the lions share of the cut then they ain't got much left but taxes and paying an attorney.

smart move by the hip hop producers and not to mention said Hip Hop Producer might charge up to 75 thousand for a beat.depends on there rate and how hot they are.