Play Mas, Orange Tree Theatre

Mustapha Matura's 1974 play is a celebration of liberation, both social and political, and a sly warning about the possible pitfalls of sudden freedom. Mas (or Masquerade) is the Trinidadian version of Carnival, an exotic mixture of Christian and African tradition played out just before Lent. It provides an opportunity to adopt a different persona, to drink to excess and to behave in ways unacceptable at any other time.

But Matura's play is set on either side of colonial Trinidad's liberation from Britain in 1962; the acting out of roles and dressing up as policemen and generals takes on a new significance.

The first half of Play Mas has the feel of a successful sit-com. Ramjohn Gookool is a tailor of Indian heritage with ambitions of owning his own business. In reality he is under his mother's thumb and spends a good deal of time reminiscing about American films with his put-upon assistant, Samuel. Ramjohn is proud of his skill and tends to see his cinematic heroes in terms of their suits: he goes into minute detail about Robert Mitchum's sartorial arrangements, preferring the cut of his sleeve to his acting. This section is full of the joshing humour that comes from the interaction of characters in a believable long-term inter-dependent relationship.  Johann Myers as Gookool has an expressive face made for comedy, Melanie La Barrie as his mother (both pictured right) is a small dynamo and Seun Shote as Samuel represents the repressed workers who are finding a political voice.  Samuel insists he is Trinidadian - even English - rather than African, while Gookool (disparagingly referred to as a "coolie") declares that he too is Trinidadian rather than Indian. The cultural mix of the soon-to-be-ex colony is clear in this workroom.

Mas transforms everyone. Samuel terrifies his employer as a convincing gun-toting marine, the local doctor becomes a witch doctor festooned with pelts and feathers, and a pair of undertakers turn up who may or may not be for real.

After the interval, set quite a few years years later, Samuel now has real authority as the new Commissioner of Police, lording it at his desk under the portrait of the first president, Eric Williams. Matura focuses on the pettiness of those new to power and luxury: Samuel's elegantly dressed wife demands a chauffeur and the opportunity to open a bazaar. (Later, got up sexily for mas, she forgets her pretensions.) This section could be a satire on any small-town politicians, but there is, of course, more at stake here.

Director Paulette Randall, like Matura a force of many years standing in UK black theatre (including as former artistic director of Talawa and as associate director of the Olympics opening ceremony in 2012), matches the tone of the writing perfectly. The effect is of sparky comedy with hints of a sinister undertow. Designer Libby Watson's mas costumes are spectacular and Al Ashford's steel-pan sound design brings Trinidad into the intimate in-the-round acting space.

It is surprising that this is the first major revival of Play Mas, which won Matura the Evening Standard's Most Promising Playwright award. It is exuberant, funny and often charming. The final scene is deliberately ambiguous as enthusiastic drinking continues against the explosive sounds of mas fireworks - or is that revolution? There seems to be a desire - but not quite the will - in the play to face head-on the new state's challenges of corruption and violence and its problematic relationship with America. This is more than a historical resuscitation, however; there is still a great deal to enjoy here.

• Play Mas at the Orange Tree Theatre until 11 April