Jonny Greenwood’s place in the music firmament is well established after three decades as lead guitarist of Radiohead. But he has built a parallel career composing film scores that threatens to eclipse his day job. His recent soundtrack for Paul Thomas Anderson’s Phantom Thread, his fourth collaboration with the film-maker, earned him an Oscar nomination this year, and he provides a another distinctive and eclectic score for Lynne Ramsay’s latest, You Were Never Really Here. Taking time off from his dual career, Greenwood answers readers’ questions about cinema, music, guitars and fighting. Steve Rose

Jessie Jones: Working for film obviously uses a different skill set, even ethos, when producing music as there’s always an image that you’re accompanying. I’m just wondering if that’s affected your work with Radiohead. The band, I think, has a very visual soundscape anyway, but I wonder how has working with film influenced that?

Jonny Greenwood: The visual side of Radiohead comes from Thom and [artist] Stanley Donwood working together while we’re recording – often in the same room – on canvas, paper, computers. And it evolves while the recording evolves (and gets Thom occupied while the rest of us try out wayward ideas to dismay/delight him with). So no, I never think in visual terms when Radiohead are working. But on soundtrack work, I do get motivated by the interesting syntheses between music and picture. When that stuff falls well together, it’s really exciting. Apart from anything, it makes the music so much better (and sometimes the picture, too).

Lynne Ramsay’s You Were Never Really Here. Photograph: Allstar/FILM4

chaspegg: Are there any films you wished you scored?

JG: That’s tough to answer – not many good films have bad scores, and I wouldn’t hope to improve the good ones. There are some silent films I love, like Häxan, which would be fun to have a go at. Or maybe do The Piano without the piano. I don’t know. I’m pretty delighted to get the gigs with Lynne Ramsay and PTA [Paul Thomas Anderson].

TheJoyOfEssex: Who is the hardest member of Radiohead?

JG: It’s not a very strong field. Having said that, Ed’s had boxing training – he was sparring with the head of our concert security on the last tour – so he’s probably quite tasty. But also the most placatory and pacific of all of us. I reckon Philip would be pretty handy if he had his wild up with someone. Unlikely, but still, don’t push him. The rest of us are … not a threat.

ID9147645: Couple of questions: how did you first cross paths with PTA and begin this fruitful collaboration for his films, but also his Radiohead videos?

JG: He saw the first film I scored, called Bodysong, which lead him to bootleg recordings of the first “classical” things I wrote: Smear for the London Sinfonietta and Popcorn Superhet Receiver for the BBC Concert Orchestra. He used bits of them in There Will Be Blood, and asked me to write more. He’s still asking, the rube.

ID9147645: Also what guitar work are you most proud of in Radiohead (that guitar squiggle in the second verse of Subterranean Homesick Alien gets me every single darn time)

JG: Sweet of you to say. Thanks. I’m more proud of what we’ve written than how I play. Ful Stop has good phasing arpeggios which are really satisfying. Also, talking of PTA, I like the version of Present Tense he filmed with me and Thom, performing in his back garden. That’s a nice guitar line, how it supports the song and dances around.

Deschain: If Radiohead’s music and sound was to be represented by a single film, which film would it be?

JG: Still on the PTA jag, his Punch-Drunk Love is very Radiohead.

Gruingrass: When was the last time you were moved to tears by a song/music?

JG: I played lots of Sibelius in the Thames Vale Youth Orchestra, and forgot about it for a few years. Now I’m getting back into it loads. The 2nd, 5th and 7th symphonies especially. It’s probably extra-emotional to me because of my teenage associations with it, and how long ago that was.

Daniel Day-Lewis in There Will Be Blood. Photograph: Allstar/MIRAMAX

CynthiaCortez: Hello Jonny, how different it is working with PTA and Lynne Ramsey (both great directors)? PS. Hope you kept the plectrum that I gave you in Miami 2017 show. Bless!

JG: Thanks for the plectrum. I keep losing them too. PTA and Lynne are quite similar really – very dedicated, enthusiastic about music, with much nerdy film knowledge. I should get them together – I think that’d make for a fun (and long) night out. You’re right about Lynne being great, though. She is very underrated – I certainly don’t know a better UK director. An amazing photographer.

MinusZero: It’s great that you’re doing film scores, writing orchestral pieces and being critically acclaimed, but do you still get days when you want to strap on your guitar, turn the amp up to 11 and just rock?

JG: I know! Of course. Nothing’s more exciting than playing an electric guitar in a small room with a good drummer. And sometimes it’s worth recording what you play, and sharing that with other people – just not always.

Karsten Walter: What key aspects and experience would you say you took from your time in Radiohead into your score creation and visa versa?

JG: I got access to string players, and the chance to write little parts for them. I think the first one was the middle eight for My Iron Lung on The Bends. On later albums the parts got longer and more prominent. It was a really good way to learn.

Karsten Walter: And could you make a solo album that’s just like Idioteque for nearly an hour?

JG: Idioteque is actually made from a short chunk in an hour-long – “performance” isn’t the word – aimless arseing around with modular synthesisers and turntables. In any case, it’s not worth hearing. Thom slogged through it and found that little section that became the basis for that one song. He didn’t look very refreshed when he’d finished. I don’t think you’d enjoy all 60 minutes.

•You Were Never Really Here is on release now.