TIL that for the film "Deliverance", Warner Bros. took the song "Feudin' Banjos" and renamed it "Dueling Banjos", to avoid giving the original composer credit. He sued and received "substantial royalties". :
Smothers Brothers : Poor Wandering One/Dueling Banjos - video Dailymotion
Waltzing Matilda | The Smothers Brothers | The Smothers Brothers Comedy Hour - YouTube