Take Barry Humphries' two formidable creations of Dame Edna Everage and Sir Les Patterson, throw in the Royal Philharmonic Concert Orchestra and renowned composer-conductor Carl Davis CBE and you might wonder what could possibly go wrong.

Well initially nothing does - its all very promising as the band strike up an elongated deconstruction of Waltzing Matilda which reaches a stirring Antipodean climax as Sir Les takes the stage in full evening dress, albeit with stains adorning his trousers in all the wrong places, and a wonderfully monstrous trouser bulge stretching to his knee.

His initial interaction with the crowd is where the show really worked; Humphries is merciless with latecomers and his Patterson character latches onto blondes with relish, trying to negotiate a bit of aftershow fun. Sprinkle in a few cracking gags and everyone is happy.

However it's clear the orchestra - and Brighton Festival Chorus - have not turned up just to watch, and it's not long until Sir Les embarks on a knowing pastiche of Prokofiev's 'Peter and the Wolf' with an Aussie equivalant, 'Peter and the Shark'. It's an intricate score that is clever and well executed - the real problem here is that it's not very funny, and goes on and on until my thoughts were wandering as to how I could beat the rush for the bar. At the interval I overheard a few grumbles, but the promise of Dame Edna in the second half was enough to suppress any revolt.

Dame Edna duly took the stage to a notably better reception than Sir Les and again our hopes are raised as she tears into terrified audience members and offers her wisdom with customary modesty. But there is an elephant in the room, and we know the musical bit must be imminent. Indeed it is and thankfully it's better - less complex, more choruses and hilariously interrupted by Everage's mobile going off. It is fellow royalty Camilla Parker-Bowles and Edna earnestly asks, 'Camilla, is it urgent? I'm doing a cantata.' Alan Bennett would be proud of that one.

However if I'm honest I'm scratching around for the belly laugh moments. The production has altogether more to do with the actual Last Night of the Proms than I suspect most of the audience ever expected. I'm not sure how this was marketed, but I certainly got the impression that a lot of the audience had come to see two hours of stand-up or 'An audience with...' style format.

What you actually get is a full musical production in which Humphries merely takes the lead. There must be upwards of a hundred people on stage and even the Brighton Centre's notorious acoustics can't diminish the impressive power of everyone in full voice. This is a production that really belongs in a concert hall, but I guess The Dome was simply too small to accommodate all the players, and indeed the economics in the smaller venues just wouldn't stack up. Seeing this somewhere like The Albert Hall would add another dimension - seeing it in The Brighton Centre left many, I fear, slightly underwhelmed.

I did get a gladioli though...