As director, co-writer, co-producer and star of Beyond the Sea, a movie about singer/songwriter Bobby Darin, who died in 1973 at the age of 37, Kevin Spacey (who's already 45) comes very close to outsmarting himself. He doesn't, though, and it's not by accident. Spacey, it turns out, is a dazzling song-and-dance man who dares to say something that aficionados of his protagonist might not like: Except for his fame and talent, Bobby Darin led an extraordinarily ordinary life.
Beyond the Sea opens vaguely like Citizen Kane: Who is this man, and how do the threads of his life converge to create the moment we witness? To mark his 10th anniversary as a performer, Darin walks onto a nightclub stage and asks the audience to guess his opening song. But they know and we know: It's "Mack the Knife," the song they, and we, all came to hear. And so the mirror reflects back and forth on itself, as an inside joke (for the nightclub audience), and as an "outside" one (for the movie audience).
And then, one more twist: It's not a "real" nightclub. It's a movie set, with Darin starring in a film about his life. He's not sure how to tell his story until he gets some advice from the child actor (William Ullrich) who plays himself as a boy.
From there, Beyond the Sea largely abandons its postmodern framing device and settles into the barest of chronological bio-pics. Young Bobby (Ullrich again) has rheumatic fever and may not live past age 16. His mother (Brenda Blethyn), a former vaudevillian, encourages him to embrace music to enrich his life. He becomes a singer, writes "Splish Splash," becomes a teen idol, writes more songs, makes movies, marries Sandra Dee (Kate Bosworth), has ups and downs, etc. etc. etc. This all happens very fast.
In other words, by show-biz standards, it's an ordinary life. "Memories are like moonbeams," Darin says: "You can do with them what you want." This gives Beyond the Sea a lot of room to invent. Darin doesn't struggle to become famous, doesn't suffer much, doesn't screw around, doesn't kill himself (a heart condition causes his early death). Not much of a movie there. But lordy, could that guy sing! And so can the guy who resurrects him.
This isn't the weary, whiney, cinema-Spacey, but rather the exhilarating actor we've seen on stage. He clearly loves Darin's music, and he loves loving it. The copious songs in Beyond the Sea present a catalogue of ways to do music on screen: on nightclub stages, in realistic settings, in fantasy musical production numbers, or in combinations of all three. Camp can be in the eye of both the beheld and the beholder, and it needn't necessarily involve ridicule. In that sense, Beyond the Sea is a work of camp -- a work of artifice, but in a thoroughly entertaining and admirable way. 
