THE LONDON FRINGE: It may not mean a thing, but it does have that swing

Plots, who needs 'em? Murray Horwitz and Richard Maltby Jnr certainly don't. Ain't Misbehavin', their loving tribute to Fats Waller, now exuberantly revived at the Tricycle Theatre, dispenses with plot, narrative, characterisation - everything yo u mightexpect from a musical, except music.

Unlike, say, Five Guys Named Moe, which incorporates the slenderest of storylines on which to hang Louis Jordan's hits, Ain't Misbehavin' is a whirlwind tour, segueing from one song to another without pausing for breath, never mind narrative, biographical detail or explanation. It takes a little while to adjust to this fact - for the first few numbers you keep expecting the show to start - but once you realise that it's songs all the way, there's nothing to do but sit back and enjoy. To resist would beas pointless as standing in the way of a steamroller.

Maltby and Horwitz do more, however, than just string together the great man's greatest hits. Some of his best loved songs are there - "Ain't Misbehavin'", "The Joint Is Jumpin'" and so on - but the compilers have also resurrected many lesser-known works, showing how broad was his talent and how various his skills. Naughtiness abounds: "The Viper's Drag", a sinuous, sleazy little discovery given a wonderful, languorous performance by Sean Palmer, opens with the line "I dreamed of a reefer five feet long ", and many of the songs are brazenly suggestive. The show switches mood with the music, helped by Bunny Christie's quick-change, stylised set which suggests low-life and high-life with equal ease. It's an evocative portrait, not an impersonation.

This musical stands or falls by the performances, which, in Nicolas Kent and Gillian Gregory's production, are a joy. The six-strong cast and four-piece band use up more energy than the Blackpool illuminations, but they also have polish and brio. They mug, flirt and work wonderfully as an ensemble, but each performer has a strength: Dawn Hope is minxy and vivacious, Debby Bishop oozes sensuality and Melanie E Marshall has a superb, rich voice and a presence that holds the stage. And amidst all the vitality, the company also does a beautiful, moving performance of "Black and Blue". Occasionally you feel bludgeoned by the relentless energy of it all, but this is a splendid, uplifting show.

There is no plot to speak of either at BAC, where Ridiculusmus attempts to translate Flann O'Brien's At Swim-Two-Birds into stage terms. Many feel adaptations of novels clog up the stages where new writing should flourish - but if you want to pay tributeto a novel, is it brave or foolhardy to choose one that is impossible to adapt?

Sad to say that, on this occasion, the decision proves foolhardy. The company tries to match the ingenuity of the original (frames within frames, diversions, multiple endings and a cast of characters who mutiny and execute their author) with an equivalent playfulness on stage. They are talented performers and the production is very inventive, but it doesn't work: it just emerges as rather messy and unsatisfying. It would be good to see them strap their evident ingenuity and ability to a more feasible project.

Sarah Hemming