There's a moment in This Is It when the creative director explains that they wanted to bring all the "big fish into the same pond". They did, and then some. In fact, it was gearing up to be one of the world's greatest live performances, a collaboration of music, dance and film of Cirque du Soleil proportions.

Thankfully it was captured on film, though the rolling out of said film just four months after Jackson's death (and in perfect time for the Christmas DVD market) says more about the mercenary actions of the Michael Jackson estate than it does the power of its protagonist.

This is a feature film masquerading as a documentary. It was made using 80 hours of footage shot during the rehearsals for what would be his 50-show tour, only the final edit was decided by Michael Jackson Inc, and not an independent editor.

The opening credits claim the rehearsals were recorded for Jackson's private library, but the slick camera angles and director Kenny Ortega's CV as a Hollywood filmmaker would indicate otherwise.

There's also the feeling that some of the talking head sequences were recorded after, and not before, his death. The film opens to the odes of his principle dancers and, assuming they aren't aspiring actors too, it seems heavily scripted and over-dramatic. In fact, you'd be forgiven for thinking you were watching Eminem's Eight Mile.

Which isn't to say that there aren't flashes of insight. The film shows Jackson to be a visceral performer who tried to reach into the souls of those around him. Every movement, every bar, every note comes straight from his solar plexus.

He lived in his imagination and he relentlessly chased his own vision. He regularly directed his musicians to let the beats "simmer" and "sizzle" and, best of all, "bathe in the moonlight".

Some ageing artists unwittingly compete with the up-and-comings who share the stage with them. Jackson gave it over to them. There's a touching moment when he encourages his 24-year-old guitar player, Orianthi, to rock out a guitar solo. "It's your time to shine," he tells her. "We'll be right there with you."

We all know Jackson was a Peter Pan figure, but This Is It shows how his every childlike whim was pandered too, perhaps too much.

The film is fraught with nerves and uncertainty. Ortega treated Jackson like a child who was prone to holding his breath when he didn't get his own way. There's the feeling that Ortega knew they might not be bringing the show on the road.

He's petrified when Jackson steps into the cherry picker during one rehearsal. In another, he makes sure someone is waiting for him with a flashlight when he leaves the stage.

Jackson always performed from his soul, but it becomes obvious that his soul had a hole in it. During one rehearsal sequence his moves become sharp and aggressive and he starts to sing the words to the lullaby-like Human Nature through gritted teeth.

When you're poor, you're mad and when you're rich, you're eccentric. Jackson was surrounded by a string of yes-men who would never have dared to discuss his very obvious prescription drug addiction.

Still, This Is It shows that he had an electric energy which just couldn't be dulled. It is a homage to his creative genius and it is the comeback he so wanted, the way he would have wanted it.

- Katie Byrne