The Trachtenburg Family Slideshow Players, Soho Theatre, London

That a band can accurately describe what they do without resorting to cliché is refreshing. The Trachtenburg Family Slideshow Players describe themselves as "an indie-vaudeville conceptual art-rock pop band" who "take vintage slide-collections found at estate sales, garage sales, thrift stores etc, and turn the lives of anonymous strangers into pop-rock musical exposés". And they do just that.

That a band can accurately describe what they do without resorting to cliché is refreshing. The Trachtenburg Family Slideshow Players describe themselves as "an indie-vaudeville conceptual art-rock pop band" who "take vintage slide-collections found at estate sales, garage sales, thrift stores etc, and turn the lives of anonymous strangers into pop-rock musical exposés". And they do just that.

How they sound, aurally and stylistically, is less clear. Comparisons have been made to Jonathan Richman & The Modern Lovers, They Might Be Giants and the late 1960s cartoon tie-in pop band The Archies. Certainly, the appearance of the family has a cartoon quality to it, somewhere between The Flintstones and a less macabre Addams Family.

Tonight, the whole family are clad in gold lamé suits. Dad Jason alternates between keyboard and guitar and fills in the gaps with his nervy, geeky Woody Allen-esque patter ("After this song your lives may never be the same again... well, who knows. I mean, let's just see"); his 10-year-old daughter Rachel looks forever unmoved as she pounds on the drums; and mum Tina Pina, who sings only on the Trachtenburgs' theme tune, takes her vital role of keeping the slides coming.

Songs such as "Mountain Trip to Japan 1959" are pretty self-explanatory. Elsewhere, the lyrics flow, or rather ramble, pretty much as an image-aided stream of consciousness, such as on "Middle America" (a collection of 1970s traffic-education slides) and "It Must Be Somebody's Birthday", with poses of people in various states of celebration and inebriation.

The pièce de résistance is the six-song "rock opera" based on an internal report by McDonald's into its market share, very much guided by the anodyne comments in the report, which spawn titles such as "What Will the Corporation Do?" and "Opnad Contribution Study Committee Report, June 1977". We have left behind the kitsch humour and humanity that manage to rise above Jason's fairground keyboard sound and his daughter's drum thud, and segued into tedium.

Jason jokes at one point that bands these days don't do reprises because all their songs sound the same, but the Trachtenburgs are guilty of this too. The banter is cute, and the dubious Q&A format provides some lighter moments, but overall the ditties aren't memorable enough.

Comedy luminaries such as Demetri Martin, Daniel Kitson, Richard Herring and Chris Addison have weighed in with their praise for this kooky troupe since their Edinburgh debut this year, and it is easy to see why they are cult cabaret. Yet, after five years of developing the soundtrack and working with the material that's projected, the Trachtenburgs have yet to realise the full potential of what they do.

To 23 December (0870 429 6883)