JamsBio Magazine has a list of 10 Songs That Resemble Other Songs. Fourth on the list is The Flaming Lips’ perhaps unintentional reuse of the melody of Cat Stevens’ “Father and Son” for their song “Fight Test”.
There are strong similarities between “Fight Test” and Cat Stevens’s 1970 song “Father and Son.” Stevens, now Yusuf Islam, is receiving royalties following a relatively noncontentious settlement. Lips’ frontman, Wayne Coyne, claims that he was unaware of the songs’ similarities until producer Dave Fridmann pointed them out.
The site contains MP3s of both songs for your comparison.