A tape loop that outlived the song

Four bars. That was the whole song for two years — four bars and a shrug.

Then the tape stretched, the pitch sagged a quarter-tone on every pass, and suddenly the four bars weren't repeating; they were returning, a little more tired each time, like a dog doing laps of a yard it loves. I let it run. Forty minutes later I had the b-side of Tape 004 and no song, which is the best trade I've made.