Sufjan Stevens has never owned a tuxedo, or worn one, or wanted to. He’s not sure how the walk on the red carpet actually works. But that’s soon to change, all because the Italian director, Luca Guadagnino, came knocking in 2015, and asked Mr. Stevens, a whispery balladeer who likes to wear giant angel wings onstage, to write a song for his film “Call Me by Your Name.”

Mr. Stevens had long resisted writing music for the screen, but Mr. Guadagnino is his kind of aesthete, so Mr. Stevens said yes. He ended up writing two songs, including “Mystery of Love,” which, to Mr. Stevens’ lasting astonishment, landed an Oscar nomination for best song.

“It’s a huge honor they’ve decided to acknowledge something expressed in a very still, small voice,” said Mr. Stevens, speaking by phone this past weekend, “It’s so absurd that I’m a part of all this at all.”