Unconventional music film Love & Mercy was a challenge for John Cusack and Paul Giamatti

Wouldn't it be nice, Beach Boys fans have thought for years, if they could wake up to find music great Brian Wilson on the big screen? And to do so while he tangles with ghosts and a deliciously malevolent doctor - God only knows what we'd do with such a film.

Actors John Cusack and Paul Giamatti make just that kind of music in Love & Mercy, their tale of The Beach Boys' tunesmith. In the unconventional biopic, directed by producer-financier William Pohlad and serving as the first major narrative piece on Wilson, the actor who once held a boom box up to America conjures up the famous Beach Boy, while one of Hollywood's more established character actors infuses Wilson's tormentor, psychologist Eugene Landy, with a sense of anxious evil.

"The problem," Cusack says, "was that no one is going to believe a lot of this was for real. It's so much more bizarre than you could actually show."

Giamatti chimes in: "This was not a man who was a whole lot of fun to play."

As conceived and written by veteran director and screenwriter Oren Moverman (the Bob Dylan film I'm Not There, most pertinently), the fact-based drama intercuts two tracks of Wilson's life. There's Paul Dano as a young, pre- Pet Sounds Wilson pressing for bold arrangements as fame and family pressure unravel him.