With a microphone in one hand and a megaphone in the other, Kevin Spacey presents Beyond The Sea, a refreshingly off-beat biopic of lounge crooner Bobby Darin. Charting his ascent from 50s bubblegum pop to his tuxedo-clad heyday in the 60s, and hippy rebirth in the 70s, Spacey weaves real-life drama with musical set-pieces to create a vibrant and whimsical portrait. Still, after the curtain drops, there's a nagging sense of something missing.

A sickly boy, Walden Robert Cassotto (William Ullrich) is told he'll never see his 15th birthday, sparking a quest for immortality that sees him become 'Bobby Darin' (Kevin Spacey), a chart-topping act with rock'n'roll ditty Splish Splash. Not content with teen idol status, however, he shoots for movie stardom and finds himself cast opposite cutesy pie Sandra Dee (Kate Bosworth).

"SPACEY SINGS UP A STORM"

She becomes his long-suffering wife, watching her own star plummet as Darin soars with an album of big band standards (including Mack The Knife) and even bags an Oscar nomination. Nonetheless he remains unsatisfied and when old health problems resurface, Darin fears that he'll never achieve true fulfilment.

Spacey hits a professional high note as Darin, singing up a storm and capturing the tragedy of boundless ambition - despite being too old for the part. His visible creakiness renders intimate scenes with the bouncy Bosworth slightly cringe-worthy, but their dynamic mostly suffers because, as director, he uses elaborate musical sequences to paper over gaps in his knowledge about their relationship.

Even so, there's much to enjoy in the mix of fantasy and reality. Besides energetic song-and-dance numbers, Darin's exchanges with his younger self (an endearing Ullrich) are surprisingly poignant. Likewise Spacey treats the darker aspects of Darin's life with sensitivity, thankfully avoiding a descent into melodrama. It occasionally drifts off course, but for the most part Beyond The Sea is a buoyant tribute.