I woke up one night at three o'clock in the morning, startled awake by the realisation that I must get dressed and take my Nagra, which is the sound recorder, and I must go to the Coalinga Pass, in Los Angeles, we were living in Los Angeles at the time, and I must record something there. And so, I got out of bed, I started getting dressed, and Aggie said, 'What are you doing?' I said, 'I'm going out to record something, I'll be back in an hour.' And she knew enough about the crazy film business to say, 'Be careful, have a nice time.'

So, I jumped on the motorcycle, strapped the Nagra to the back of the motorcycle, and went off to the Coalinga Pass, which is the mountain pass between the San Fernando Valley and Los Angeles proper. And Route 101, the main North South route in California, crosses the Coalinga Pass. And, there's a bridge in the middle of the pass, which I knew about. And I positioned myself on the bridge, took out the Nagra, turned the Nagra on, and I heard the sound that without knowing what I wanted to hear, as soon as I heard I thought, 'This is exactly correct.' And there was virtually no traffic at that time of day. But coming from behind me, was a tractor trailer, a semi, I think in the States an eighteen-wheel truck, empty. And it was going somewhere, and it was going somewhere very fast, and it zoomed underneath me. I was on the bridge and the road was below, and it zoomed underneath me and rocketed down the other side of the valley, way off into the distance. And because there was no other traffic at the time, and because I was recording it, I heard it until it disappeared off into the far horizon, it was the only sound. And, it was making a sound that was perfect for what I wanted, which was a kind of a singing sound. Because it was empty, because it had eighteen wheels, the wheels were making a musical sound, and they were bouncing because of the emptiness of it, and so it was sounding... Way off into the distance. And, I got to the end, finally I couldn't hear it anymore and I turned the Nagra off. Got on the motorcycle drove home and crawled back into bed at four o'clock in the morning. And she said, 'Did you get it?' 'Yes I got it.' 'That's nice, dear.'