You should listen to the hidden messages in Pink Floyd songs, cause they are really hidden messages that was put there on purpose, when you listen to them normally, you cant tell what is in it, but you play it reverse, it changes to real words...

for example, on the song "Empty spaces" from the album "The wall" in the middle of the song you hear Roger Waters voice saying something but its not clear, but when you play it reverse, you clearly here something like: "Congratulations! you've found the secret message, please call old pink to get you prize..." or something like that.

another one, is on Roger Waters solo album "Amused to death" on the song "Perfect sense - part 1" there is a hidden message from Waters to Stanley Kubrick calling him a BOOK BURNER!