There are few theme tunes more iconic than The Rockford Files: funky, jazzy, upbeat and brimming with vigour, it's space-age synths and breezy harmonica heralded the wonderfully laid-back adventures of Jim Rockford, played by James Garner. More concerned with character and humour than detective-work, The Rockford Files was a show about nothing, long before Seinfeld, and has a special place in TV history.

Badback Mountain is two men, Liam Grundy and Jonathan Holloway, whose show is billed as a homage to Garner and co. Like the adventures of Jim and Rocky, it opens with an answer phone message, and at one point Holloway dons a wig for a vague impression of Rockford guest-star Stephanie Powers. But the real point of connection that the Badback boys are trying to establish is that their show is also about nothing. Some songs, some banter about not having prepared a show, and that's your lot. It's even suggested that the idea of performing at the fringe is actually just a pre-text for a heist on the Pleasance's box-office.

The banter sometimes hits the spot. References to a 'static caravan in Musselburgh' occasionally evoke the right kind of quiet desperation, and the maybe presence on-stage of a stuffed cat called Brexit might fall under the heading of topicality. And it has to be said that the songs are short, sweet and very good indeed – nicely played and easy to enjoy.

But, and it's a 'but' worth starting a sentence with, this isn't much of a homage to The Rockford Files. Playing the fabled theme at the start and finish doesn't make this feel any less of a 'bait and switch'. It's a shame, because Liam Grundy's bar-room rock/country stylings are more than enough excuse for a show, and one that's likely to be of considerably less interest to Universal Television's copyright department.

Pleasance Dome, until Aug 26, (not 13, 20), 2.50pm, £8.50–£11 (£7.50–£10).