Directed by the Tony Award winner Michael Mayer (“Spring Awakening”), with a libretto by the playwright Nicholas Wright and starring the elegant mezzo-soprano Sasha Cooke, “Marnie” has high stakes for Mr. Muhly and the two companies producing it. New operas are artistic and financial risks, and the gamble is particularly significant for English National Opera, which has suffered funding cuts and major management upheaval over the last two years.

Image The poster art for “Marnie,” which stars the mezzo-soprano Sasha Cooke.

But Mr. Muhly, 36, has built a reputation and fan base that stretch across traditional genre lines. In college he worked as an assistant to Philip Glass, and he has collaborated with pop artists like Björk and Anohni, the songwriter and singer formerly known as Antony Hegarty, while producing a considerable and well-regarded oeuvre of orchestral and chamber works, as well as numerous scores for dance.

The idea for “Marnie” came from Mr. Mayer, who saw the film on television shortly after directing “Rigoletto” at the Met. Mr. Muhly said that after reading the book, he realized “it would make a perfect opera.”

In a wide-ranging interview, he spoke about the way music can tell a story that words cannot and how women must constantly negotiate their identities. Here are edited excerpts from the conversation.

How did you approach adapting the story to opera?

It was Nicholas Wright who determined the narrative structure. There are emotional notes you have to hit: her relationship with her husband, her connection to her horse. And then internal notes you have to hit.