That secret "Wing Mario Over the Rainbow" level is such a pain in the ass to complete.
Title: Super Mario 64 Wing Cap Theme
Original composer: Koji Kondo
Cover by: Daniel "Kuhneghetz" Ohlsson
Tracker used: FamiTracker
SoundChip used: RP2A03 (Nes NTSC), VRC6
A playable NSF of this song can be downloaded here:
http://2a03.free.fr/dl.php?file=5384