Three weeks before There Will Be Blood first hits select screens in the US, the Paul Thomas Anderson film is already one of the most talked-about films of the year, not least for its haunting score by Jonny Greenwood. Nonesuch Radio recently added to its playlist two tracks from the score—"Open Spaces" and "Future Markets"—which you can hear now (click Radio icon at left). Today the Nonesuch Journal brings you an exclusive interview with the composer, in which he discusses everything from his musical influences—from Penderecki to the Pixies—to his use of the ondes martenot, an early electronic instrument found in such seminal 20th-century works as Messiaen's Turangalîla-Symphonie. Nonesuch will release the complete There Will Be Blood soundtrack December 18.

In previous interviews and your earlier orchestral works, you have expressed admiration for the music of modern composers like Olivier Messiaen, Gyorgy Ligeti, Krystof Penderecki, and Paul Lansky, among others. Could tell us more about how you were introduced to these composers' music, and how often you still listen to their music today?

I first heard Messiaen when I was 15 or 16—the Turangalîla-Symphonie—and just found it magical, especially with the ondes martenot swooping around with the strings (who seemed to be playing an entirely different piece of music). I didn't know it was allowed to write music like that. Also, it was the fact that he was still alive, still writing. I just latched on to him, partly in reaction to all the schlemiels who only liked twee classical music, but mainly because it was such other-worldly music.

Because of this I came to think of Messiaen and my favourite bands—like The Pixies, New Order, The Fall—as all being in the same category somehow ... and I still do.

Penderecki I heard in the three weeks I was at music college. I'm glad I did ... with his music, it's hard to accept there's only “traditional” instruments being played. I saw him conduct his Viola Concerto and just couldn't believe it was only strings on stage. Where was that noise coming from? Where were the speakers?

Which other "classical" works, recordings, and composers might it surprise a fan of yours to learn are old favorites or staples of your regular listening?

I'm a sucker for French music in general—I suppose France was always cooler than anywhere else, even in 1910—so Ravel, Debussy, through to Messiaen and Dutilleux all have this shimmering magic to them.

Could you describe the process that led to the score for There Will Be Blood? Did you watch the film or read the Upton Sinclair novel Oil!, on which it’s based, once or twice before the music began suggesting itself to you, or did the imagery and storyline reveal musical themes from the outset?

I saw some fairly long sections of the film, read the script, and just wrote loads of music. I tried to write to the scenery, and the story rather then specific “themes” for characters. It's not really the kind of narrative that would suit that. It was all about the underlying menace in the film, the greed, and that against the fucked up, oppressive religious mood—and this kid in the middle of it all. Only a couple of the parts were written for specific scenes. I was happier writing lots of music for the film/story, and having PTA [Paul Thomas Anderson] fit some of it to the film.

Has writing pieces for orchestra and chamber ensemble always been an ambition of yours, or is it something that has developed over time?

I was hooked when I joined a youth orchestra briefly in my teens and heard, for the first time, a room full of string players actually playing in tune. It's an incredible sound. I guess it's a shame for most of my stuff they have to play out of tune ... but still ...

You are almost certainly the only rock star to play the ondes martenot, which also figures prominently in the score to There Will Be Blood. How did you first come to discover this instrument, and what does it add to your music that is different from by more traditional instruments?

It makes the theremin look like a toy. I think the theremin is a toy. The ondes martenot is all about control; there's no guessing, or random gestures. It's a true musical instrument, and people who play it well can make it sing. It's like the inventor approached it with the idea "How can we play music with electricity?"

You have mentioned the special kind of magic that happens in a concert hall when an orchestra is playing together. Are orchestral concerts something you still have time and interest to see? How much live music of all kinds do you still go to?

I've not seen anything live since we started the last Radiohead album, but there's a Messiaen festival coming up, and I'll be there for it all, if I can. It's an addictive experience. [The Southbank Centre kicks off a yearlong festival celebrating Messiaen's centenary beginning February 1, 2008.]

If time, money, and personnel were no issue, what would be your ideal medium for a future classical/concert music work? A Mahlerian symphony of a thousand, or something smaller-scale, such as a string quartet or solo instrumental work?

I think string quartets are perfect. Hearing individual players so clearly makes for more expressive music. I think that's why we didn't use many of the “orchestrated” string quartets for this album, even though we recorded them all. I like to be reminded that there are individuals behind the sound you're hearing.

What was playing in your CD player or iPod most recently?

Junior Kimbrough: Sad Days, Lonely Nights. It's a great blues album. Makes you realise how intricate and subtle that music is, after growing up in the UK and thinking that blues was just overblown pub rock with endless guitar solos.

What is on your must-do list for a trip to New York City?

Lots and lots of walking.