So, what is this? Casey Bennetto, the author of Keating! and one of the lead actors in it, says that it was first written as a "performance piece". The production at the Belvoir St Theatre is longer, with new songs and characters, and is a "show". Nowhere is it called a musical, though it is a completely song-driven piece of theatre. In effect, it's a revue, a very good one that at times seems to strive for something grander, a little like Keating himself; reality, a need for a few more strong songs, and the arrival of John Howard bring it all back to earth.

Keating! is performed in two halves, the first 30 minutes of each the strongest parts of the night. It begins with Terry Serio coming on as Bob Hawke, doing him in full leering Sir Les Patterson mode. It's a crude, thrusting portrait, drawn so to establish the high ground for the arrival of the star of the show. Ladies and gentlemen, the amazing Paul Keating! And what an entrance Mike McLeish, playing him, makes. Framed in a high doorway, leaning against a wall, leg up, immaculate in a black suit and tie, and young, his first line - "Hi, I'm Paul" - brings the house down.

Here's the kick. Bring Keating back from jowled middle age, keep the Italian wardrobe and the glint in the eye, and play him as part Rat Pack cool, part Jeff Koons geek. Let him dance and let him sing, just like all smartly dressed young men do in musicals. But instead of songs of love and happiness and dreams, have him sing policy: reconciliation, Asia, the possibilities of a republic. He's a song-and-dance man, but a song-and-dance man with ideas about the future of Australia. And it is Bennetto's genius to see this in Paul Keating: his innate smoothness and oddness, a perfect fit for a leading man, especially when played young. The dreams are more poignant, the downfall never far away.

The show covers Keating's takeover from Hawke, his seeing off of Hewson and Downer, a swerve to visit the Evans-Kernot affair, and the defeat by John Howard. This was a rich time in politics. All the leading participants were big, ideal for the satirist, perfect for a production interested in the bizarre and hungry to draw as many parallels as possible between the bump and grind of show business and the bump and grind of Canberra. The events of the period, though, still remain in relief, because this is an affectionate and at times almost camp study of Keating, and is at its best when it stays focused on him.

Mike McLeish gives him a youthfulness he never had in public life. Both Hawke and Howard are played as much older, or closer to their actual ages. Keating is given a generation-splitting zest, the young man of the story with a vision and the ability to use those shiny black shoes to do a bit of serious dancing. McLeish is stunning in the title role, and as long as he is on stage, the show does not flag. He has the confidence and flair to grab the central idea and run a mile with it. All the ruthlessness, energy and passion Keating had is there, ramped up under the spotlight. McLeish's singing is clear and not overpowering, and when it reaches or strains, it does so in the heat of the moment.

The parameters of the venue produce a much more intimate show than I was expecting. The cast is primarily three people - Bennetto, Serio and McLeish - the former two doubling in roles. The music is played live by a five-piece band, and the lighting and stage-setting are simple and effective. It's all ‘revue' dimensions, with built-in production ideas hinting at where it could go in a bigger space. The band is a revelation. They wander on with patrons still filing in, and drop into a funky groove based on Bob Marley's ‘I Shot the Sheriff'. Straight up, you can see that no one overplays; they are mostly young guys, and there is a verve and lightness to their playing not usually associated with the theatre. It's a good innovation to put a band of this kind into this situation, bypassing the usual piano or brass, and have their cool, versatile music fill the room.