Mojo, Harold Pinter Theatre

I first saw Mojo as a film, adapted from the stage and directed by its writer Jez Butterworth in 1997. And it really didn’t work. Set in 1950s Soho and involving club owners, gangsters and a wannabe rock & roll star, it tried too hard, felt flashy and stilted; the period proved a graveyard in much the same way as it did for Absolute Beginners a decade before.

How wonderful, then, to see Mojo where it belongs, on stage, with its original director again at the helm and a killer cast that relishes the material. For it truly is a fabulous play, which demonstrates that at 25 Butterworth already possessed the tools that would lead to Jerusalem – the rich, dexterous use of language, the brio, the keen sense of Englishness, a facility to switch between comedy and danger – or to contain them in the same moment – that made the casting of Harold Pinter in the film version so obvious. It’s an original, vibrant, gloriously entertaining piece of work.

It takes place entirely in a Soho club, one which is jumping on the bandwagon of the fledgling music revolution. The play opens in the upstairs office, where silver-suited and suitably quiffed singer Silver Johnny (Tom Rhys Harries) is fine-tuning his strut before going on stage. We can hear the pulsating music below, sense the excitement of his teeny audience; when he rushes down the stairs, the lights go out and the volume’s racked up, the play launches like a take-off at Houston.

With danger outside the door, inside they threaten to destroy themselves We return to the office and a pair of low-level club employees, Potts (Daniel Mays) and Sweets (Rupert Grint), who are waiting expectantly on the results of a meeting behind closed doors. Their boss Ezra is discussing the future of Silver Johnny with Mr Ross, a “flush man”. Potts imagines that since he discovered the singer, he will win a slice of the pie; his sidekick is already swimming in reflected glory. Drinking and popping pills – these characters pop a lot of pills – they could be Vladimir and Estragon, better dressed and with a roof over their heads, but waiting in vain and no less doomed.

Mays and Grint (the latter in his stage debut) make a lovely comedy double act, one darkly quiffed and mustachioed, the other of course ginger; one voluble, smart and ambitious, the other a bit dim. Their scene together is a canny one, lulling us into a false sense of security, before more volatile characters take the stage.

We will never meet Ezra. Overnight the life of the club is turned inside out and his staff, including right-hand man Mickey (Brendan Coyle), Skinny (Colin Morgan) and Ezra’s son Baby (Ben Whishaw, pictured right) find themselves under siege. With danger outside the door, inside they threaten to destroy themselves, the temperature raised in particular by the sexual tension between Baby, who may well be a psychopath, and Skinny, who really shouldn’t be copying Baby’s wardrobe.

Director and long-term Butterworth collaborator Ian Rickson has the knack (and restraint) to stage the plays in such a way that allows the language and characters to weave a spell unencumbered by undue theatricality.

Ably assisted by designer Ultz, he captures the milieu with deceptive simplicity – the first half taking place in a workaday office whose only notably objects are not one but three jukeboxes, the second in the club below, the two floors connected in our minds by a spiral staircase that the actors glide up and down in a way that is worth a hundred workouts. Soho is evoked by morning light pouring through the shutters, or by the text itself – Baby’s observation of “a Buick in Dean Street” speaks volumes.

The production is chock full of star power. It’s some event when you can reference James Bond (Whishaw’s Q), Harry Potter (Grint), Downton Abbey (Coyle) and Merlin (Morgan) together on the London stage. Get past the novelty, and one finds a cracking ensemble.

When Baby demands that the other man “Kiss my pegs” you don’t know whether to laugh or run for the hills Whishaw bristles with menace as Baby, whose taunting of Morgan’s scheming and possibly lovestruck Skinny provides some of the play’s most outrageous moments – not least when the lights come up to a chaotic party binge, Skinny tied to a juke box with his trousers around his ankles and Baby brandishing a cutlass before him. When Baby demands that the other man “Kiss my pegs” you don’t know whether to laugh or run for the hills.

Grint acquits himself well, although I’d welcome the day when he gets to play a character like Baby. And Coyle’s familiar world weariness anchors the action. But Mays is the stand-out, a revelation even as the motormouth, vainglorious, ultimately pathetic Potts. He’s incredibly funny, combining finely-honed physical comedy with a delicious attack on the words.

And Potts gets many of the best lines, among them a sigh of dawn despair as this bravura tale of young men caught between rock & roll rebellion and old school villainy enters its final stretch. “I’ve had nothing but sorrow and birthday cake since sun up. So stop the music hall.”

• Mojo at The Harold Pinter Theatre to 25 January 2014