Some Kind of Monster, a new documentary about iconic heavy-metal group Metallica, will undoubtedly inspire some comparisons to the seminal mockumentary This is Spinal Tap.

And to some degree, that's valid. Both are movies depicting a band struggling to come to terms with the fact that, because of all of the changes around them and within them since their founding, they can never be the same band they once were, for better or for worse. So there are some moments of Spinal Tap-ish absurdity, enough that when frontman James Hetfield points to his amplifier and says that it was the first he ever owned, you half expect him to add, "This one goes up to 11." But this movie deserves much more than shallow comparisons.

Indeed, Some Kind of Monster is ultimately the best of what a documentary can be, an insightful but never judgmental look into something closed to the average citizen. It is a depiction, a real, in-depth depiction of how an album is made from start to finish, a process which very few people will ever get to see, and that comprises much of its allure.

To be sure, directors Joe Berlinger and Bruce Sinofsky benefit from the mystique that surrounds the making of an album, as well as the turmoil which just happened to surround Metallica as the movie was filmed -- the departure of bassist Jason Newsted, Hetfield's year-long trip to rehab and the band's nearly continuous sessions with a therapist, Phil Towle, and the problems that arise as he tries to inject himself deeper and deeper into the band.

Their real genius, however, comes through in the deft way Berlinger and Sinofsky handle all that. The filmmakers were at a disadvantage in making this movie -- there's no suspense to be had, since anyone who watches MTV News knows how it ends. Berlinger and Sinofsky could have stepped in, imposed a narrative structure, a lead to some sort of definitive ending answer. But instead, they step back, letting the myriad questions that arise through the film -- Can you make loud, angry music and film your music video in San Quentin prison while selling your Jean-Michel Basquiat painting for $5 million? Can a heavy metal band which thrived on wildness and alcohol survive old age, children and rehab? -- hang in the air. And those unanswered questions serve as the conflict and the suspense which drives the movie.

In fact, it is that air of uncertainty which hangs over this film that will probably repel those who should be most interested -- Metallica fans. For the die-hard fans, watching the band in these situations will probably be painful. For the rest of us, it's a thrilling experience.