In 2021, the singer-songwriter Aimee Mann (perhaps best known, as a solo artist, for her contributions to the Paul Thomas Anderson film Magnolia) released an album called Queens of the Summer Hotel, a collection of somewhat narrative tunes inspired by Susanna Kaysen’s bestselling memoir of mental health struggle, Girl, Interrupted. Mann had been commissioned to write the songs for a stage adaptation that took years (and the duration of a pandemic) to materialize. Now finally at the Public Theater in Manhattan, Girl, Interrupted is a sturdy showcase for Mann’s gorgeous, shimmering-sad compositions, but perhaps a less successful conduit for Kaysen’s arguments.

The press materials for Girl, Interrupted are careful to stress one point of distinction: this is a “play with music”, not, strictly, a musical. The former term has been around for a long time, but eludes exact definition. It’s a “know it when you see it” (or hear it) kind of a thing. Girl, Interrupted, though, fits rather comfortably under the rubric of the traditional musical. The songs may not advance the plot, exactly, but they do offer crucial insight into the inner lives of the troubled young women encountered by a fictionalized Susanna at McLean, a storied psychiatric hospital in suburban Boston.

Susanna (Juliana Canfield) arrives there in 1967, having survived a suicide attempt (aspirin chased with vodka was her method of choice) and needing, in the polite euphemism of the day, a “rest”. She is immediately introduced to an array of young women with differing ailments: charismatic Lisa (King Princess) has been diagnosed a sociopath; Susanna’s roommate Grace (Mia Pak) is a stable-seeming person who has schizophrenia; Daisy (Katherine Reis) has obsessive issues related to eating; Polly (Sally Shaw) is covered in burn scars from having lit herself on fire.

These characters will be familiar to those who’ve seen James Mangold’s 1999 film adaptation (for which Angelina Jolie, who played Lisa, won an Oscar). But this stage version has tamped down much of the movie’s cinematic overstatement: here, the characters dwell much closer to Earth. Which might have played somewhat flat were it not for Mann’s songs, spare but poetic arias and duets that let us drift inside the minds and hearts of these passionate, confused people.

Particularly striking are Burn It Out, in which Polly attempts to explain the thinking behind her horrific act of self-mutilation, and Robert Lowell and Sylvia Plath, sung by Susanna and Grace as they contemplate the fine line between creative genius and madness, evoking two famous former McLean patients. Each song is sung in rich and melancholy tones, accompanied by varying combinations of piano, violin and guitar (some of which are played by the actors). Girl, Interrupted is an austere chamber piece, and yet its moments of music briefly access a vastness of abstract thought.

Director Jo Bonney’s staging is simple, judiciously employing a turntable and a few chairs. (Heather Gilbert’s lighting design helps create individual spaces and moods.) At times one yearns for more energy, some showwomanship that might turn up the temperature. But Bonney and playwright Martyna Majok are determined in their restraint. The end result is that we maybe don’t feel the weight of Kaysen’s conclusions about her experience as powerfully as we should. Any deeper meaning is kept at a remove, delicate and feathery in the middle distance. What lessons or ideas we are meant to take away from the piece are very much ours to suss out afterward.

Still, Canfield – who worked such play-with-music wonders two seasons ago in Stereophonic – does her noble best to illuminate Susanna’s condition. She holds the center of the play with a quiet, intelligent firmness, selling us on the production’s reflective, half-dispassionate conceit. This is adult Susanna looking back at a moment in her life that she still does not fully comprehend. All she knows for certain is that there was woefully little understanding of, or genuine interest in, the inner lives of young women at that time, a fact she confronts with a sort of wry resignation.

King Princess, a recording artist as well as an actor, takes the flashiest role and shrewdly underplays it. Quite unlike Jolie’s lupine, prowling take on the character, this Lisa is calmer, more fellow traveler than domineering alpha. But we do feel her magnetic pull nonetheless; it is not hard to grasp why she is so often the focus of the group’s attention and devotion.

And yet, I would like to know Lisa, and all these fascinating people, a bit better – when they are not singing, anyway. Girl, Interrupted is elegant, often engaging theater. But it lilts through its world rather than diving into it. Perhaps the calculation was that Mann has done enough to deepen the story through song. In that case, this is more “music with a play attached” than the other way around.