The tape Jerry had was a stereo mix with the bass and guitar coming out of the left speaker and the drums and vocal track on the right.

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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.

NPR: The Mix Tape: Art and Artifact