Vinyl Data
The history of Vinyl Data has some surprises. I didn't realize there were artists encoding Sinclair ZX Spectrum programs into their records as far back as 1983 such as Pete Shelly from the Buzzcocks and the Thompson Twins. That's awful hardcore for 20+ years ago. I would say it beats the crap out of manipulating spectrograms.
Even more awesomely The Thompson Twins included an adventure game (called The Thompson Twins Adventure) where you wander around beaches and caves for no real reason:
You can actually play it online here. OH GOD I FOUND A BOTTLE OF SPICE.
My favorite of course is Urusei Yatsura's 'Everybody Loves Uresei Yatsura' album:
Examining the source for the program reveals the following comments:
"Hi Nick, is Robin there?""Judas Priest Satanic Message #3"
"What is sadder: a.) finding this b.) writing it"
Lick his cloven hoof.\m/ (via kotaku)