Starring John Cusack. Rated PG.

By now, everyone knows that Brian Wilson spent years playing (and sleeping) in a sandbox. How he got there, and finally got out, is the subject of this bracingly original biopic, which limits itself to two key periods in the head Beach Boy’s life.

Parallel time tracks follow a beefed-up Paul Dano, excellent as Wilson at the mid-’60s start of the SoCal band’s wild ride to the top of the AM–radio wave, and John Cusack as the drugged-up Brian, 20 years older and struggling to escape Svengali-like “therapist” Eugene Landy (a maniacal Paul Giamatti). This binocular effect is initially jarring, especially with Cusack’s usual shoe-polish hair in place of Wilson’s characteristic sandy mop. (Imagine how well Philip Seymour Hoffman would have fit this role.)

The latter period centres on the divorced songwriter’s meeting with future wife Melinda, a Cadillac saleswoman and former model played by Elizabeth Banks. Her sexy turn, coupled with Cusack’s innate charm, helps explain their mutual attraction. This isn’t really explored in the script by Michael A. Lerner, a sometime journalist and son of My Fair Lady composer Alan Lerner, and Oren Moverman, who wrote more complicated stuff for the Dylan-based I’m Not There.

Given its two-hour running time, the film also shortchanges Wilson’s brothers—most notably tragic Dennis, the only charismatic Beach Boy—allotting more space to odious cousin Mike Love (Jake Abel). This loss, however, is thrillingly offset by miraculous re-creations of many amazing studio sessions (from “Help Me, Rhonda” to “Good Vibrations”) masterminded by the young Brian. Most are filmed at (the former) United Western Recorders and other accurate locations, and executed by musicians who resemble key members of the Wrecking Crew (like Teresa Cowles as killer bassist Carol Kaye).

It’s clear that this arena is closest to the heart of novice director Bill Pohlad, producer of such substantial titles as The Tree of Life and 12 Years a Slave. He takes an appropriately impressionistic approach to Wilson’s psychological problems, mostly stemming from physical and emotional abuse at the hands of father and manager Murry (Bill Camp), who whacked young Brian hard enough to deafen him in one ear.

The smartly crafted Love & Mercy makes it clear that Wilson’s genius in no way benefited from his torment. We would have had even better music without it.