'I listen to Messiaen's work over and over – and once stole from him. But only one bar'

I first heard Messiaen when I was beginning to get to know the man who is now my husband, Jörn Weisbrodt. Jörn was working at the Staatsoper in Berlin. One day he brought home this amazing recording of an opera called Saint-François d'Assise and put it on.

I knew the big 19th-century opera composers – Verdi, Wagner – and also some of the great modern works such as Berg's Lulu and Britten's Peter Grimes. But I'd never properly listened to Messiaen. From the first chord, it was a revelation: music that felt utterly ancient and also completely contemporary. It was so intense. It transcended all the boundaries.

Like so much of his music, the opera, which is about the life of Saint Francis, was inspired by Messiaen's religious belief. He was a devout Catholic and played the organ every week at a church in Paris. There's something enormously passionate and direct about the way he wrote. He loved birds and made special compositional trips to the south of France to listen to birdsong, and he put a lot of the sounds he heard directly into the music. You don't feel it's a gimmick; it's something his musicality forced him to explore.

Messiaen also had synaesthesia, which in some people manifests as the ability to "see" music as colour, and you can sense that in his music somehow. He makes chords sound both dissonant and melodic. They're pure and clear to listen to – and a lot of his melodies are hugely singable – yet, when you look at the score, you realise they're hugely complicated. The fine line that he walks between the tonal and the atonal is so beautifully done. And it's such sensual, seductive music: his Turangalîla Symphony has a slow movement that's pure Hollywood.

'I listen and let it sink into me' … Rufus Wainwright on Messiaen's Quartet for the End of Time. Photograph: Tim Knox for the Guardian

Right now, I'm listening to the Quartet for the End of Time. I've been working through it for the last year or two. I'm very slow – I listen over and over again and let it sink into me. Messiaen wrote the piece in a prisoner of war camp after being captured by the German army in 1940. It's scored for violin, cello, clarinet and piano, because those were the only instruments he had available, and was premiered in the camp in front of German officers, with Messiaen himself and other prisoners playing. It's remarkable music, sometimes fierce and angry, at other times almost hypnotic. What's incredible is how positive it sounds: there's sadness there, a huge amount of emotion, but it sounds optimistic. It doesn't sound destroyed.

Messiaen has influenced me as a composer and songwriter in all sorts of ways; you can't listen to someone so much and not be influenced. And I did borrow one of his ideas once. There's a section in my opera Prima Donna where someone is asking the heroine for a signature, and I wanted to see what it would be like to write a musical "autograph". I found a moment from Saint-François d'Assise, and used that. So I stole from Messiaen. But only one bar.

As I get older, I find his music means more and more to me. My mother is no longer with us, I'm married, and Jörn and I now have a beautiful daughter. Things begin to rest a little more heavily on you. There's something about the span of a life; you need to go to the masters. They're the only ones who can encapsulate the simple things.

Olivier Messiaen (10 December 1908 – 27 April 1992)

Way in: Quartet for the End of Time

Key work: Turangalîla-symphonie

In three words: Mystic. Radical. Ornithologist.

Soundbite: "Birds are the greatest musicians on our planet."