At the NPR site, read the introduction to Sonic Youth guitarist/singer Thurston Moore's new book "Mix Tape: The Art of Cassette Culture":
...I made what I thought was the most killer hardcore tape ever. I wrote 'H' on one side, and 'C' on the other. That night, while we were in bed, and after Kim had fallen asleep, I put the cassette on our stereo cassette player, dragged one of the little speakers over to the bed, and listened to the tape at ultra-low thrash volume. I was in a state of humming bliss. This music had every cell and fiber in my body on heavy sizzle mode. It was sweet.