The Last Impresario, the new documentary from first-time feature maker Gracie Otto, begins with a casual stroll around the promenade during the Cannes film festival. All of a sudden, actors, directors and other stars of varying backgrounds and talents gather round one man; a sunglasses-wearing old chap. His face isn’t one we’ve seen on film posters, on the stage, or on TV. That’s because his name is Michael White – he’s the man behind the posters, and possibly some of your favourite movies. He is an Impresario, perhaps the last of his kind, and he won’t go down without a fight – or a glass of Moët.

The most famous man you’ve never heard of, Michael White is the Godfather of the modern theatre scene. Responsible for influential musicals such as Oh! Calcutta! and The Rocky Horror Show (which of course went on to spawn its own cult cinema legacy), while forging his name in the movies as a producing force behind classics Monty Python & The Holy Grail and My Dinner With Andre, White’s legacy is one that obviously goes as deep as contemporary entertainment culture does. And while Otto’s film aims to encapsulate the man, it draws on far too straight a biographical grammar to illuminate this compelling figure at the centre of the swirling, exciting heart of showbizness.

Once White’s childhood in Switzerland is rapidly dispensed with, his career is depicted as forming near-instantaneously; little is made of the friendships White makes along the way, or his emotional stake in it all, as we zip past early success after early success until it becomes sucked up into the same vortex of excess. And White was into his excess, too; he’s portrayed as a womaniser, but a kindly one. A man of endless parties, who would come back in the early hours of the morning no matter what the occasion called for. And too often, we’re treated to tumbling montages of all the famous faces White has touched in his career, but these segments act as arbitrary tissue in the place of actual substance. What of the man?

Well, thankfully, toward the end of The Last Impresario, the man himself finally comes into the light. Otto documents White’s current state, bravely attending all the parties of his youth (Cannes being one of them) even after suffering a series of strokes, is touching; it’s this portrait of White that the movie excels at, tenderly showing an old man who refuses, rather commendably and understandably, to grow up. It’s this awkward balancing of genuine insight versus showy flipbook-history that lets the documentary down; what more exciting thematic gold to be mined than White’s Peter Pan complex? Of course, it comes too little, and far too late, to even out the rest of the film’s problems.

Ultimately, what Otto has done is make two different documentaries; the young, hip theatre producer who grabs life by its huge horns and rides it into indulgence and legacy; the old, past-his-prime theatre producer who rejects his own mortality. One of them is better than the other, and considerably so – but that one half is worth seeing, and you’ll remember the name ‘White’ from now on.