Reminds me of some stuff Robert was doing MANY years ago (late 70's early 80's) when I was doing radio at WAIF.  He did a short tour of record stores, just him and two tape recorders.  He threaded a reel from one machine across it's heads onto the SECOND machine, across its heads and then on its take up reel.  The first machine was in record mode and the second in playback.  The distance between the machines controlled the delay time.  He played while a full reel of tape was recorded on one channel.  He then rewound the reel, and played back the recorded track while recording on the second channel (both on machine one) and the second machine was in playback mode as well still providing a delayed output, this time of BOTH tracks. The effect was mesmerizing to say the least.  If I remember correctly, as a third pass instead of rewinding the tape, he took the reel off machine two and flipped it over and put it on machine one and repeated the process.

Gary Shell