Parodies and tributes of the Fab Four have a long history, from The Rutles onwards, but there’s always mileage in having another stab if you’re creative with it. Disappointingly, The Dung Beatles have simply aimed low with cheap smut, and by randomly mashing-up real Beatles history with pure invention have created a messy storyline, when a more structured approach might have guided them, and us.

Introducing… is set-up as an interview between the world’s worst Beatles tribute band (actually a duo) and Helen, a news anchor on her way down the career ladder. We get musical flashbacks from their career, with only the vaguest of timelines to hold it together.

Each song is a single filthy concept stretched out for a few verses. We open with Fist and Shout and then it’s boobs and pubes all the way. Not wanting to give any spoilers, I Wanna Hold Your Gland and The Long and Winding Choad are two songs that don’t feature but might as well have done. Essentially, it’s #MakeABeatlesSongRude turned into a show. The pun title and the tune are the only things derived from the original. Scansion, phraseology, place in the canon are all sacrificed if it gets in the way.

Adam (only very tenuously the Lennon of the two) is a guitar player; Scott (McCartney?) is presumably not. This sets up a weak, running gag about an invisible bass, which if it must be persisted with should at least be a left-handed one.

They snaffle a few bits of actual Beatles history, such as the Apple rooftop gig and the Ed Sullivan appearance, but then graft in stuff they just made up, like a trip to Machu Pichu, to work in an un-Beatles related pun. There is so much scope for a Yoko figure, a Maharishi, anything that would just bind the story together more coherently.

The troupe are a plucky young trio and instinctively you’re rooting for them, but you wonder how much exposure this has had beyond the bubble in which it was created before it arrived at the Fringe. The backstory of the reporter, whereby she was forced off her prime-time job for refusing to drop puns into her sign off, shows promise. It would sit very well in a more diverse sketch show, of which some tighter, sharper Beatles related material could be part. But instead they’re mainly reaching for the cheap snigger and are willing to play fast and loose with the basic Beatles concept to get to it. Fair play to them for taking a punt on the Free Fringe, but you wish they’d steered this in a more fruitful direction.