Max Stafford-Clark premiered Timberlake Wertenbaker's 1988 play about a colony of convicts in New South Wales rehearsing a production of The Recruiting Officer with a parallel production of the Restoration comedy itself, and the same crew of actors.

His definitive revival for his Out of Joint company, 25 years on, is as persuasive of the play's qualities as was his recent re-visiting of  Caryl Churchill's Top Girls; neither play needed rehabilitation, exactly, but both can triumphantly claim "modern classic" status.

Our Country's Good is going to carry renewed impact at a time of cuts and the economic - some say politically motivated - threat to arts activities in schools and indeed prisons; the glorious second act of this play is a metaphorical hymn to the act of making theatre in a community that has learned to define itself in the process.

And this really happened: George Farquhar's great comedy was the first theatrical performance in Australia, acted by a bunch of English convicts in Sydney Cove in 1789. These convicts had been spared the gallows by transportation to a distant prison camp. The theatrical link was ingeniously introduced by Thomas Keneally's great novel The Playmaker, the source of Wertenbaker's play.

The other great book in the background is Robert Hughes' The Fatal Shore, a majestic account of the social experiment that Wertenbaker presents in such vivid detail, though the set-up of characters at first seems emphatically Manichean, black and white. The playing does nothing to undermine that feeling.

But Stafford-Clark's swift production, simply played on a raised wooden platform with ropes, pulleys and beautifully dyed swags (neat work by designer Tim Shortall), soon creates an interactive ensemble out of thieves and officers, culminating in Dominic Thorburn's second lieutenant Ralph Clark embracing Laura dos Santos' spirited Mary Brenham (in rehearsal as the disguised Silvia) on Farquhar's line, "There's something in this fellow that charms me."

Doing plays makes people feel better about each other, even to falling in love. And doubling roles, endemic to the whole exercise, enriches your character, as proven by John Hollingworth as both the first Governor General, Captain Arthur Phillip, and the Jewish criminal Wisehammer who's swallowed a dictionary, and by Ian Redford as a blustery old captain, sweating midshipman and haunted prisoner.

Some scenes are played to illustrate a point, or a crisis, as in Brecht, others allowed to develop into fully integrated expressions of tribunal, rehearsal and confrontation. Kathryn O'Reilly's sullen Liz Mordern ("I didn't steal the food") is measured for the gallows like Brecht's Galileo for his robes, while the "cast" burst into a scene from the play to distract attention from offstage brutality: culture as palliative.

The play is simple yet many-layered and resonant, historical and modern, gritty and theatrical, didactic and emotionally engaging. At times it seems as though written in blocks, but the blocks begin to merge. It's simply one of the best plays of the past 50 years, ending in a yelp of delight and a volley of Beethoven.