The swinging sixties were the heyday of freethinking theatre troupe People Show, which burst onto the scene with innovative, multi-disciplinary comic performance devised through democratic collaboration. Half a century later, the company’s offering is rather less radical, almost slightly anachronistic, but there’s still something wonderfully charming about this zany, energetic music hall entertainment.

The Detective Show creators Gareth Brierley, Mark Long, Fiona Creese and Sadie Cook (with only the latter not also doubling as a performer) wisely include several different strands of comedy in their loose collection of sketches, so if farce, mime and dodgy disguises aren’t to your taste, there’s also meta humour, surrealism and frequent breaking of the fourth wall for post-modern asides.

While not all of the gags land, the hit rate in a breathless 70-minute show ensures there’s more than enough to satisfy, and the talented trio just about maintain a deliberately obtuse murder mystery plot while tearing through costume changes and flinging themselves into slapstick set-ups. Director Jessica Worrall keeps the chaos in check while allowing for an enjoyably anarchic atmosphere.

Where the show occasionally runs into difficulty is its lack of specificity. With a dizzying range of genre targets, from Agatha Christie and Prime Suspect to a combination of Cluedo and The Seventh Seal, there’s confusion about the main subject of enthusiastic lampooning and whether or not to abandon its storytelling blocks altogether. You’ll find more precise skewering in Charlie Brooker’s A Touch of Cloth on Sky or in West End juggernauts One Man, Two Guvnors and The 39 Steps, and a better mastery of multiple characters in something like Stones in His Pockets.

However, the deconstruction of theatrical conventions is generally on the money. Among my favourites were an explanation for the gulf between programme notes and the actual content of a performance, and the always-reliable jobbing actor gibes. That insider humour makes the show feel a tad less dated and occasionally offers glimmers of real emotion, particularly from Gareth Brierley’s unctuous narrator.

Founding company member Mark Long, in contrast, is firmly old school, with his combination of wild stereotypes (including a gesticulating waiter more studiously Italian than Strictly’s Bruno Tonioli) and rubber-limbed physical comedy. The combination ensures there’s something for everybody, even if the hodgepodge approach keeps this from being more than a fun diversion.

People Show 121: The Detective Show, at Old Red Lion Theatre

People Show, the UK's longest-running alternative theatre company, offer a wonderfully silly whodunit pastiche in their 121st outing. At the Old Red Lion Theatre.