It’s also a stunning feat of scoring by Adjmi — whose hypernaturalistic script captures the ebb and flow of overlapping speech both inside and outside the studio’s sound room — and by director Daniel Aukin and composer Will Butler. Aukin and the show’s stellar cast play Adjmi’s rigorously constructed, deceptively casual prose with as much exactness and audacity as the actors, all playing their instruments live, pour into Butler’s songs: Smart, well-crafted tunes that blend the folk and blues and prog vibes of the ’70s with the soaring indie yearning of Butler’s former band, Arcade Fire. (There’s a cast album on the way.) The show is part concert and part breakup drama, part sound-design marvel (Ryan Rumery is the hero responsible) and part beautifully observed period piece (everyone’s legs look dynamite in Enver Chakartash’s bells and flares, and that lovingly intricate set is by David Zinn). But it’s the thing Adjmi conjures up at the end of Act One that makes Stereophonic such a meaningful and exceptional piece of work: In its bones, it’s a love song, bittersweet and wounded and ferociously loyal, to the act of making art — specifically, art that requires that most exhausting, infuriating, transcendent element: collaboration.