Michael Jackson in concert -- almost

Judging by his reputation, Michael Jackson had many personalities. We got a glimpse of one of them when we learned about Jackson's personal Xanadu, Neverland Ranch. We saw another when Jackson was forced to drag himself into a Los Angeles courtroom as the cable TV cameras rolled. Over the years, we watched Jackson grow up or maybe we watched him not grow up, but in the broadest sense, two Jacksons seem indelibly sketched on a pop canvas that spread over four decades: Michael Jackson, freak and Michael Jackson, entertainer.

It's the latter Michael Jackson who's on view in This Is It, an exciting concert film assembled from more than 100 hours of video footage shot during rehearsals for Jackson's London show, the one he was on the verge of opening when he died last June at the age of 50.

Shot in high definition and equipped with a masterfully recorded soundtrack, This Is It reveals little about Jackson, the man. It's not so much a backstage documentary as an on-stage documentary, a series of performances, many of which seem fairly polished. It makes you wonder. Maybe for Jackson, there were no off-stage moments.

Of course, there are rehearsal-level compromises. The dancers and Jackson mostly aren't wearing the costumes that were being prepared for the show, and at various times, Jackson sings softly to preserve his voice. He also gives instructions to his keyboardist and musical director, telling him to play a lick as if it were dragging itself out of bed. At another point, he asks for more funk from a bassist, but there are few unguarded Michael moments on view.

Expect no diva-like tantrums or major revelations. What you get is music and a taste of how lavish the show might have been.

Late in the proceedings, Jackson introduces an environmental theme: He expresses a love for trees that would have made Joyce Kilmer blush. This environmental rap sounds as if it had been recorded elsewhere and slipped into the film to allow for a transition to a performance of Jackson's Earth Song.

Still, it's almost as if director Kenny Oretega -- who also directed the stage production -- knew that a documentary eventually would emerge from all the video footage, which we're told at the outset originally was intended for Jackson's personal use.

Skillfully combining footage from various rehearsals, Ortega gives us relatively seamless numbers, where none may have existed. And Jackson fans will take a musical journey that includes favorites such as Thriller, Billie Jean, Man in the Mirror and even a splashy tribute to the Jackson Five.

Those unfamiliar with Jackson's concerts may be surprised by the scale and apparent expense of productions that become inseparable from the music. Thriller, for example, mixes live performance and 3-D horror footage shot for the occasion. Smooth Criminal makes use of Rita Hayworth's sultry performance of Put the Blame on Mame in Gilda.

There's also lots of dancing -- from Jackson, as well as from dancers who seemed thrilled to have the opportunity to perform with the King of Pop and who serve as a kind of impromptu claque when Jackson performs alone.

I'm not sure how This Is It would have stacked up against other Jackson tours, but the movie is entertaining, and it does justice to Jackson, the entertainer.

Is there something exploitative about a film that follows quickly on the heels of Jackson's death? Probably. But This Is It serves as a reminder that whatever else Jackson may have been, he was one hell of a performer. His fans will turn out, and I doubt that they'll be disappointed. I wasn't.