I'VE got a bit of a thing about Sibelius's Fifth Symphony. That's where I got the idea of a single melody happening in different places throughout a piece, but in disguised forms. There's a wonderful moment in the last movement of the symphony where this great tune is going on, and the bass line is playing the same melody, only at a quarter of the speed. And out of that, the thing builds into an amazing crescendo, yet not quite in the way you expect. In the coincidence of the melodies, you keep hearing what sound like jazz-type chords - major sevenths. So it sounds strange and yet it's completely intermeshed. I like the way you're given lots of different ways of looking at the melody. I certainly borrowed that idea - a repeated pattern which seems to throw out all number of melodies in repetition. At the start of Tubular Bells II, I found this really simple little keyboard figure, but when you repeat it over a long period, it's almost like it comes apart and starts to sound like several melodies going on at the same time. I kind of got that from Sibelius's Fifth Symphony. I used to listen to the John Barbirolli version with the Halle Orchestra. The performance is stunning - everything really comes together. You've got an orchestra of about 120 people and if it was a bad performance, probably half of them would be thinking about their tea-break or the football. It makes you realise how a conductor is worth his salt.