Creedence Clearwater’s John Fogerty had to take his case all the way to the supreme court. Rights to one of his early songs were bought by a record company who tried to legally prevent him from performing or writing any song in a similar style.
He won eventually after spending over a million legal dollars and not being able to perform his own music for many YEARS.
I recommend seeing him perfom live now if any chance arises.
http://en.wikipedia.org/wiki/Fogerty_v._Fantasy,_Inc.
I thought it was more complicated than that and had to do with the other band members who basically screwed him over.