Spamalot likes to have it both ways – both mercilessly mocking the conventions of stage musicals, and also relying on them for its success. It’s the same with the show’s connections with its parent movie, Monty Python and the Holy Grail; on the one hand it’s a fresh reinterpretation, but on the other it relies on prior knowledge of iconic scenes to appreciate how they’ve been rethought.

The unstoppable juggernaut of gags veers close to pantomime at times, with songs name-checking Mary Berry and Sharon Osborne, and even a bit of reluctant audience participation. The pace is brisk, bordering on frenetic, which means that some of the magical strangeness of the original is cast aside in favour of humour that’s a bit more mundane.

Joe Pasquale makes a surprisingly strong King Arthur, though, with a gentle nobility and bewilderment at the madness erupting around him – as well as a nice line in show-stopping ad libs. Todd Carty is luxury casting as the largely wordless Patsy, the king’s servant-cum-horse impersonator, but his shameless mugging brings alive the character’s bafflement. Things burst into vivid life, however, when Sarah Earnshaw as the Lady of the Lake is on stage – she’s spine-tingling in blues numbers and torch songs, but she’s got a finely judged sense of comedy too, especially as a stroppy diva sidelined in act two.

The rest of the ensemble are energetic and convincing – Richard Kent stands out as a gleefully un-PC, camper-than-Christmas Prince Herbert – even if the sound balance sometimes leaves their words hard to decipher. The show could probably do with a little more time and space to breathe, but as a night of musical comedy, it’s slick, smoothly delivered and ruthlessly effective.

Reviewed at The Edinburgh Playhouse, Mon 16 Mar.