Turning a true story of industrious struggle into an opera is an artistic challenge. However the drama played out at Tower Colliery in South Wales which climaxed in 1994 when 239 miners chipped in with £8,000 apiece to rescue "their pit" and turn it into a successful workers' cooperative is the stuff of theatre. It prompted the Brecon-based company Opera Box to set to work a couple of years ago with the aid of a £290,000 lottery award from the Arts Council of Wales. The result is a decidedly unstuffy production which director Brendan Wheatley says reinforces his belief that opera is not simply for posh people.

Art follows life. The part of Tyrone O'Sullivan, the National Union of Mineworkers' official who was the driving force behind the buy-out, is played by Robert Lloyd, principal bass at the Royal Opera House. "The pit will stay open," a mantra he intones throughout, becomes the opera's theme. Ann Atkinson sings the role of her namesake Ann Clwyd, the Labour MP who staged a lengthy underground sit-in to highlight the miners' cause.

Composer Alun Hoddinott and writer John Owen combine to create a potent musical drama. The set is stunning: a huge pit-wheel dominates as the action moves from coal face to pit head baths to the union office. "Eternal vigilance is the price of freedom," the union banner proclaims as the miners and their families finally celebrate victory.

Tower the opera mirrors Tower the colliery, once deemed by British Coal to be uneconomic but now turning in healthy profits and paying good wages. The opera also reflects the social history of Wales. Two male-voice choirs add volume to the production and local schoolchildren invade the stage in crowd scenes that recreate the community spirit of mining villages. After curtain calls the audience rose and sang Myfanwy, a piece as emotional as the Tower drama.

• At the Grand Theatre, Swansea, until October 30. Then touring.