Jonny Greenwood on Sam Stephenson

Jonny Greenwood doubts the writing of music can be filmed, telling the documentary maker Sam Stephenson that it would mean being with people at the most awkward and annoying point of their day. He writes at a viola or cello, or with the program Max/MSP, and sometimes panics into ideas at the last minute, and they are often his best. Orchestral writing is like a firework display, months of planning for one afternoon of hearing it, and the first run-through shows in a quarter of an hour which sections work. With Radiohead there is usually a song of Thom Yorke's, or a chord sequence Greenwood hopes will go into one of Yorke's songs, and the work is arranging, like the 500 versions of a Cole Porter song. The band is the faster hit; orchestral work is solitary, and “you get to ask yourself what do you think you're doing a lot more often”.

In early interviews he felt an idiot when asked about favourite guitarists, having to ask the interviewer who played guitar in Magazine, his favourite band, because in good bands the players serve the band. Sean Slade and Paul Kolderie, who produced Radiohead's first record, told him the Pixies rehearsed for days on end, and what they rehearsed was arranging songs so short and interesting that they never bored an audience. He never forgot it. He can't name a music documentary he has enjoyed; he says he doesn't watch any.

A second clip has him on live music. A Steve Reich piece from a couple of speakers is a big compromise once he has seen the sweat that goes into it. Eight people crowded round a couple of marimbas beat one man at a laptop making the same phasing rhythms, he thinks; it may be snobbery, but more likely it is that something can still go wrong. Raised on recordings, he finds it strange that live music is simply gone once it is played. He came to concerts the way he came to his first turntable, bought at about 20, when he had to ask the shop how styluses worked, having missed out on record players. On days off on Radiohead tours he checks the local listings, and in Alabama last time he went to hear the local symphony orchestra.