Buddy is a retired actor, and he's standing on the derelict stage of a doomed New York theatre. He used to perform there many years ago, and the place holds many memories. "Another theatre comes down," he remarks mournfully, "It's just what this city needs, another parking lot."

In Stephen Sondheim's Follies, Buddy, and several other now aging members of the Weissmann Follies theatre company, have gathered for one last reunion. And Follies is the clever choice for the reopening show at Northampton's Royal Theatre, for it brilliantly contrasts fact and fiction: the New York theatre will become a car park, whereas the Royal has undergone a major restoration - more about this in The Oxford Times soon.

Meanwhile, in New York, old hurts and passions flare up: all those years ago, Buddy and fellow actor Ben both fell for Sally, and inevitably the story did not have a happy ending. Buddy and Ben are quick to square up to each other once again as the reunion gets under way.

Follies needs a large cast, a problem that the Royal's new artistic director, Laurie Sansom, has solved in a way that is totally appropriate to the reopening of this much-loved local theatre: he has selected the Weissmann Follies singing and dancing chorus line from the ranks of Northamptonshire's amateur operatic societies. The Weissmann chorus contains some strong personalities, producing some eagerly seized cameo opportunities.

"I have my own television show," snaps improbably blond Solange (Susan Moore), annoyed when someone doesn't recognise her. "It's very hard to lose a husband - but I've lost five," remarks Hattie (Rita Gee) cheerfully. And if a few of Sondheim's top notes do occasionally prove elusive (as they would at such a reunion in real life), the chorus line most certainly produces some powerful singing, while the snappy tap routines brought the house down on opening night.

Among the professionals, Alex Giannini (Buddy), Julian Forsyth (Ben), and Louise Plowright (spurned wife Phyllis - pictured, with Ben) all deliver strong performances. But the star is Jan Hartley as Sally - her delivery of Sondheim's tricky solo numbers was particularly memorable and moving. Altogether director Sansom's amateurs and professionals merge seamlessly together.

Like all Sondheim musicals, Follies is not easy to pull off. Sansom captures Sondheim's built-in cynicism and disillusionment expertly, but he does one strange thing: instead of keeping all the reunion guests on stage together, enabling quick fire exchanges of conversation, people walk on stage, deliver their lines, then walk off again. It's like ballet couples dong their showpiece pas de deux, and it makes the first half seem too long. But overall this is a triumphant reopening show for the Royal Theatre.

Follies continues until Saturday, November 18. Tickets: 01604 624811 or www.royalandderngate.co.uk