[block_dagger]

Also see: Land O'Lakes, Morton Salt, and Cracker Jack.

[dekhn]

See also: https://www.google.com/search?q=recursion

[lgas]

Also Pink Floyd's Ummagumma album cover.

[unit149]

Look at Loveless: two amps, facing one another with a microphone embedded in between. Shields did not use any pedals for the album. Audio is recursively transformed in a synthesis of feedback loops.