Several species of small furry animals gathered together in a cave and grooving with a pict. It is rock song with the longest title and is pretty damn good - I heard it live on their Umma Gumma tour in quadraphonic stoned on acid. It still sometimes sneaks into my consciousness when I am in the wilderness (like that scene in Zatoichi when he is walking into the village before the grand finale dance scene. If you want to see some serious swordfighting, look at this or any of the original 21 Zatoichi films.)
I'm a bass player, among other instruments and one of my all time favorite bass players is a cat by the name of Stu Hamm. This is a great instrumental that I just listened to and have tried to emulate in the past.
One of my favorite progressive rock bands, Tool, has a song called Lateralus that is truly a work of art using the Fibonnaci sequence as it's vocal driver. The song has been covered by many on the Youtubes but this piece is a testament to it's art.
I last heard "Happy Birthday" because of my neighbor's 2 year old daughter's birthday. Man, they were loud in their back yard. I purposely left our backyard so i don't have to hear their voices because it hurts so bad to listen to them! Picture 30 people screaming "Happy Birthday" and a dozen babies crying.... it's annoying.