[Source: AP]

The assignment was daunting: Write a song for an onstage moment of transcendence.

Make it kind of funny and exciting and for a five-piece band. Write it so it justifies an audience sitting in their seats for two hours before they hear it. And, oh, it must plausibly be a rock hit in 1976.

That was the job facing singer-songwriter Will Butler and the music arrangers for just one of the songs that stud the Tony Award-nominated play “Stereophonic,” a leading contender at the June 16 Tony Awards.

“It’s like, ‘OK, that is a lot of things to think about, but let’s just try it out and we just tried it out,” says Butler, who left Arcade Fire in 2022 and has a new band, Sister Squares.

“Stereophonic” is playwright David Adjmi’s story of a Fleetwood Mac-like band in the mid-’70s recording music over a life-changing year, with personal rifts opening and closing and then reopening.

The music that accompanies the drama includes full-on rockers like “Masquerade” and “Drive” but also fragments and demos as the band reworks tunes. It is a wonderful slice of funky, classic rock for a fictional band that became a real one onstage.

“I was trying to get in their heads. I was also a lot of the time just trying to make a great song, which is a hard enough task. And then hopefully a great song can support many interpretations — that’s the dream.”

Butler was connected with Adjmi by a mutual friend, and they first met at a diner about 10 years ago. Butler had just moved to New York and writing for theater intrigued him. It was a relaxed meeting and they hit it off: The two talked about “Moby Dick” for an hour.

Adjmi hadn’t yet written a word of “Stereophonic.” He had the title, a vague concept and wanted it set in a recording studio. Butler over the next five years would submit “random” demos, like a song that someone might write if they listened to Phil Spector all day or one inspired by Sylvester in 1973 in San Francisco.

Once a script appeared, Adjmi leaned on Butler to fill in the song gaps. One moment had Diana, a young singer-songwriter, nervously play a new tune to her controlling boyfriend, the band’s de facto leader and guitarist.

What would it sound like? It could have been a Stevie Nicks-inspired I’m-looking-at-you takedown, more a Joni Mitchell-ish mystical journey or a Neil Young “Heart of Glass”-like approach. Butler wrote lots of options, some which ended up on his new band’s 2023 self-titled debut.

He tried to give the musicians a sonic backstory. They likely listened to Nina Simone and girl groups growing up. They likely heard Glenn Gould and folk music change from Peter, Paul and Mary into Bob Dylan.

Butler credits the whole team — Adjmi, sound designer Ryan Rumery, orchestrator and musical director Justin Craig and director Daniel Aukin — for refining and refining the songs. All have Tony nominations.

“The music that I’ve always made is just a very deep collaborative art form. And theater, by its nature, is deeply collaborative,” says Butler.

“We were all just going to have each other’s backs, and there wasn’t going to be a hierarchy. We were just going to dig in on this and work on it until it was good.”