Love and Mercy were two qualities that troubled Beach Boy Brian Wilson found in painfully short supply during a life blessed and cursed by his musical genius.

Like the Jacksons, the Wilson boys were the subject of beatings from a tyrannical father whom they adored and feared.

Brian, sensitive and insightful, suffered the most, forever seeking approval that never came. Coupled with his explorations with LSD and a vulnerability to psychosis, he was turned from a creative force to shambling husk in inverse correlation to the appreciation he was due.

The film of his life takes twin tracks, in keeping with the theme of fractured identities and kaleidoscopic realities.

There is the young Wilson (played by Paul Dano) who wants to take the surfin’ and cruisin’ fun-time band into the sort of musically complex territory occupied by the Beatles but who finds his new sounds controversial and unloved.

The 1980s Wilson (played by John Cusack) is chaperoned, drugged up and bullied (in loco parentis) by “therapist” and mule-driver Dr Eugene Landy (Paul Giamatti).

We meet the vacant musician buying a Cadillac from former model Melinda Ledbetter (Elizabeth Banks) who will become his unlikely saviour, offering him those two qualities his life had lacked and rescuing him from a life of crippling servitude.

Both stories stand alone yet both central performances give a better sense of the whole. Paul Dano has the creative fizz of youth albeit haunted by a sense of indistinct menace. Cusack plays Wilson monotoned, eccentric and sweet but essentially broken.

For fans of the music, there is plenty to delight, including insights into how those extraordinary sounds came about while director Bill Pohlad has plenty of Instagram-style fun, providing an authentic sense of period.

John Cusack and Elizabeth Banks play Brian Wilson and Melinda Ledbetter in Love & Mercy

The woozy camera work and visuals together with the (necessarily) mumble core vibe pour this Hollywood biopic into a low-key but stylish indie vessel.

The only disappointment is Giamatti playing Landy as a pantomime villain rather than canny manipulator. However, the lack of subtlety in his performance is more than compensated for by Banks who brings a moving tenderness to Wilson’s salvation. Her compassion, while hedged by wariness, has a depth that gives the piece its emotional press.

Finally, the credits roll to (the real) Brian Wilson, restored, recuperated and singing Love And Mercy to an appreciative crowd. This completes a full picture of a creative force who tragically spent half his life as half a person.