Martin Scorsese's Shine a Light looks inside the rock 'n' roll machine that is the Rolling Stones and dissects the secret of the band's success.

The centerpiece of the movie is footage from a rare theater set by the band in 2006. It makes the moving camera a part of the kinetic show. The lens sweeps and swoops, recording the rockers as they interact almost instinctively, communicating with a nod, glance or pat on the shoulder.

Interspersed between hits and rarities are contemporary footage of the band preparing for the show and film, and vintage clips of the band at every stage of its career.

It serves as a sort of shorthand, documenting the band's history and the evolution of its attitude as the shift from up-and-coming act to big business takes place.

As should always be the case with a rock doc, the most remarkable aspect of Shine a Light is the music. There are a few clunkers -- As Tears Go By is creaky, and the Christina Aguilera duet on Live With Me is creepy. For the most part, though, the songs prove that although they're not the most talented or technical of acts, there's a Rolling Stones alchemy that still works.

Perhaps the most remarkable aspect of the film is the mysterious sense of increasing vibrancy and vitality that seems to emanate from the band as the show proceeds. It's almost as though with each song, the Stones get a little younger. The attacks seem sharper, the attitude increased, even the heavy lines that now crease each Stone seem a little less pronounced.

It is perhaps the most telling clue as to why the Rolling Stones continue to matter after more than 40 years: They understand that rock continues to matter as long as the guy with the guitar still believes.