A biopic focused on Beach Boys' leader, Brian Wilson and his corrupt therapist, Dr. Eugene Landy (  / Roadside Attractions)

Like the best musical biopics, “Love & Mercy” isn’t a musical biopic. On its surface, this sensitive, multifaceted portrait is “about” Brian Wilson, best known as a co-founder of the Beach Boys and the driving force behind the band’s myriad Top 40 hits. But director Bill Pohlad, working from an exceptionally smart script by Oren Moverman and Michael Alan Lerner, takes an oblique approach to his subject, homing in on two pivotal episodes in Wilson’s life: the creation of the “Pet Sounds” album and his subsequent mental breakdown and, 20 years later, his courtship of his current wife, Melinda Ledbetter, and her efforts to help him separate from Eugene Landy, the therapist upon whom he had grown perilously dependent.

It’s a bold choice to tell a story through the prisms of timelines that never converge, and even bolder to cast two different actors to play Wilson on each trajectory. As “Love & Mercy” opens, Paul Dano plays Wilson as an exuberant but fey young man, his performance channeling every tic, riff and falsetto grace note with goosebump-inducing authenticity. Infusing his film with grainy period detail and an alternately burnished and candy-colored patina, Pohlad gracefully moves viewers through the Beach Boys’ early days, culminating in a severe anxiety attack Wilson suffered on a plane while touring. From then on, Wilson insisted on staying back in Los Angeles, writing big, ambitious songs, recording them with the legendary studio musicians known as the Wrecking Crew, and waiting for his bandmates — his brothers Carl and Dennis, cousin Mike Love and friend Al Jardine — to return and record the vocals. “Even the happy songs are sad,” a bemused Love complains in the studio. The critics don’t agree, but fun-in-the-sun fans do, and the record bombs.

John Cusack plays Wilson in the 1980s, and while he may not look as spot-on as Dano does in the role, he nonetheless conveys the musician’s damaged, guarded fragility. He walks into a Cadillac dealership and strikes up a conversation with a pretty saleswoman, who turns out to be Ledbetter. The two have an immediate connection, with Ledbetter patiently listening as Wilson stammers his way through non sequiturs and tentative, disarmingly intimate disclosures. “Lonely. Scared. Frightened,” he writes on the back of her business card, by way of introduction.

Elizabeth Banks, above, is the woman who falls in love with the older Wilson (John Cusack) and saves him from a Svengali therapist. (Francois Duhamel/Roadside Attractions)

As portrayed by Elizabeth Banks, in a warm, quietly attentive performance, Ledbetter turns into the heroine of “Love & Mercy,” which toggles between the young Wilson’s attempts to compose and record “Smile,” his follow-up to “Pet Sounds,” and her dawning awareness that Landy — played with menacing bluffness by Paul Giamatti — is slowly destroying the man she’s falling in love with. The Landy-Ledbetter chapter of Wilson’s story plays almost like a thriller, as the even-tempered blonde does cat-and-mouse battle with the manipulative psychiatrist. The early years belong solely to Wilson, who experiments with LSD, puts a sandbox in his living room and breaks open new notions of writing, arranging and instrumentation. (Wilson’s “vampire” years, when he succumbed to alcohol, drugs and obesity, are obliquely foreshadowed in a shot of Dano sitting on the edge of a swimming pool, dejected and bloated.)

These early scenes are both deliciously atmospheric and infused with incipient tension, as Wilson’s visionary genius increasingly gives way to frightening auditory hallucinations and still-palpable traces of trauma left by his abusive father. Pohlad takes an instinctive, impressionistic approach to the material, allowing viewers to hear what Wilson hears in short, tantalizing bursts of gorgeously layered chords and discordant shards of everything from a theremin to barking dogs. (Wilson’s “Smile” sessions were brilliantly, affectionately parodied by Judd Apatow in “Walk Hard” with a song called “Black Sheep,” written by Michael Andrews and “Smile” lyricist Van Dyke Parks.) One of the most thrilling scenes in “Love & Mercy” is when Dano’s Wilson is working with two Wreckers on a bit for “Good Vibrations” and Pohlad’s camera moves in a 360-degree shot of the entire studio: The shot captures both the romance of creation and the workaday routine it takes to bring it to fruition.

“Love & Mercy” is full of such scenes, in which Dano uncannily captures the ecstasy of creative gifts even Wilson himself couldn’t fathom, as well as the panic of sensing their evanescence and psychic cost. For his part, Cusack’s Wilson is undefended and shut down, peering out of his Malibu aerie to see if anyone can see him, and maybe hear what he hears.

Cinema is a dynamic medium, in which sound, image and movement are privileged. It’s difficult to make a visually dynamic movie about people listening. But that’s precisely what Pohlad has done with both sensitivity and audaciousness, on the one hand attuning his protagonist to the music of the spheres, and on the other bearing witness to his deepest isolation and sadness. By deciding not to make “Love & Mercy” a musical biopic, the filmmakers have turned Wilson’s story into what it seems to have been all along: the ad­ven­ture of one man’s arduous, terrifying, ultimately triumphant search for God.

PG-13 At area theaters. Contains thematic elements, drug use and some obscenity. 120 minutes.