George Martin on Recording "Tomorrow Never Knows"

"At that time they'd all gotten their own Grundig tape recorders, and I think it was Paul who found out that by removing the erase head and putting a loop of tape on it, you could actually play a short phrase that would saturate itself. It went round and round and overdubbed itself until the point of saturation, and that made a funny sound. When you played it back, it was cute to listen to. It was what we call musique concrète. So they all vied with each other. They each went home and made these funny little loops and they would bring various tape loops in for me to hear. They recorded them at different speeds, you know, one and seven-eighth [inches per second], three and three-quarters, seven and a half, and fifteen.

"With 'Tomorrow Never Knows' I selected eight of them and put them all on different machines. We had people all around the building connected to our control panel with these silly loops held up with bits of pencil to keep the tension going eternally. I then decided the best way to do it was to put them all through a mixer. So all the eight tracks of these loops came into our mixer and it was like an organ. By bringing up any one track you could have any loop at any time. With a 24-track machine that's a fairly common technique, but we didn't have that so it meant that when we were mixing it that was the actual performance. We had everybody on the mixer. Apart from the engineer, who was Geoff Emerick, we had Paul on a couple of faders and John on another, I was on the pan pots. We would all make a concerted mix and just do our own thing. When we felt like the seagull sound should appear, we'd put that fader up and so on. We did many mixes and then decided which was the best one."