Inventions: The Early Music Weekend, Queen Elizabeth Hall/Purcell Room, London

To what extent is the revival of early music really a tradition of the new?

To what extent is the revival of early music really a tradition of the new? Over recent seasons on the South Bank, Philip Pickett has presided over a fairly standardised series of themed medieval to Baroque spectaculars in the David Munrow tradition. But now comes the musicologist Tess Knighton, editor of Early Music, to remind us that the revival of early music has a lengthening history of its own, of constantly shifting sounds and styles as scholars and performers try every which way to bring the slender source material back to life.

Indeed, gathering together as many contrasting approaches as possible was the very point of Inventions: The Early Music Weekend - the first of the events Knighton is planning over the next three years. And hardly had she finished introducing the series to her first-night audience, scattered with their drinks among the foyer tables, than six of them upped and began passionately to sing. This proved to be the first of two performances of Monteverdi's Fourth Book of Madrigals (1603), with the singers of I Fagiolini addressing his piercingly beautiful evocations of longing, jealousy and rejection to actor-lovers moving around the very tables at which the audience was seated.

As Stephen Walsh has already written here of an earlier performance at this year's Cheltenham Festival, the dramatic intensity and musical security - 19 madrigals performed from memory - were equally impressive. But almost as involving was watching the faces at various angles of one's fellow-listeners - absorbed, startled, self-conscious, embarrassed - as the musical give and take flew inches from their ears. It brought home how much immediacy is lost by having to sit in serried ranks in the modern concert hall - the Purcell Room, for example, in which the opening evening's other event was given.

It would be hard to imagine a less flattering acoustic for the Mille Fleurs - singers Jennie Cassidy, Helen Garrison and Belinda Sykes and medieval harpist Jan Walters - nor for their programme, drawn from the Spanish 14th-century Huelgas Codex. Yet they triumphed through the intelligent variety of treatments of their material - a microcosm of Knighton's entire weekend.

The Codex, compiled for the nuns of a Cistercian monastery, comprises almost 200 short pieces in one or two parts. Some were sung "straight", some with added drones, doublings-at-the fifth, or counter-melodies, and some given as improvisational harp transcriptions. Most memorable, perhaps, was the long, slow, cumulatively ecstatic realisation of "Maria, virgo, virginum".

Mille Fleurs's recording in progress of the entire Huelgas Codex on the Signum label should be looked out for. So, too, should the ongoing renewal of early music on the South Bank.