The music teacher I had in junior high school was an interesting guy. A few us from the band used to hang around in the music room after school. One afternoon he broke out the reel-to-reel and we made a tape loop of us saying beep-boop and tapping a triangle and making other noises.
I forget the exact set up but we used some type of cylinder on a stick (a broomstick, maybe?) so that the loop was something like 10' long. I remember that we had all kinds of problems keeping the tension right so it would keep running past the heads at the right speed but we figured something out.