Dracula! (Mr Swallow - the Musical), Soho Theatre

Nick Mohammed's show has had a slight change of title since it debuted at the Edinburgh Fringe last year, where it was called Mr Swallow - the Musical, and garnered warm reviews for its shambolic silliness.

The set-up is that Mohammed’s alter-ego, the egomaniacal Mr Swallow, a lispy Northerner who is quick to take offence but is oblivious to all around him, has fashioned a musical, Dracula! - starring himself as the bloodthirsty count, of course – and we are watching the final dress rehearsal. Mr Swallow, for some reason known only to himself, makes his appearance on roller skates; it sets the tone for evening – daft, making no sense at all, but funny.

Three other actors - the director, Joseph (David Elms), who also plays Van Helsing, Kieran Hodgson as Jonathan Harker and Joanna Grace as his fiancée, Wilhamina - are taking part in the awful run-through, but are hampered by Mr Swallow's increasingly bizarre interruptions. He doesn't so much tear down the fourth wall as demolish it as he – standing camply with limp wrist - demands of the audience: “How does Dracula stand?” Well, not like that, for sure.

A play being intentionally bad is a well-worn conceitMr Swallow demands that his big song is longer than Harker's and that he has more stage time than Van Helsing, and introduces a new character that Bram Stoker might not recognise – an irritating female booking attendant at a ferry terminal, compete with blonde wig and broad Liverpudlian accent. He even alters the story so that his character doesn't die, and Mr Swallow's monumental indifference to great literature is wonderfully encapsulated by his objection to having garlic thrown at him as the Transylvanian vampire - “Jonathan, seriously, we're not bruschettas!” he cries.

A play being intentionally bad is a well-worn conceit (Michael Frayn's Noises Off being the best example) but while Mohammed doesn't exactly reinvent the form, he does at least provide some laughs playing with it. A spoof musical must also work on its own terms and, while none of the songs remotely stays with you (and some of the words can't be heard clearly over the otherwise cracking five-piece band on stage), they have some verbal finesse, for example "I'm way more famous than Jekyll / With nothing so creepy to Hyde".

It may be that I saw Dracula! on a quiet night at the Soho Theatre, when some of the bounce I remember from Edinburgh appeared to be missing and where one section of the show – in which the cast try and fail to order a Chinese meal – completely unravelled. Having said that, the hour still raised several laughs and is undemandingly good fun.

• Dracula! (Mr Swallow The Musical) is at Soho Theatre, London W1 until 7 March