Light Passing, National Centre for Early Music, York

Commissioned by BBC Radio 3, the work will be performed from October 28 to 30 in the medieval church in Walmgate, an apt setting for an opera set in medieval France.

It tells the story of Clement VI, the most brilliant of the Avignon Popes. As a spiritual leader he stood for tolerance, defending the church from bigotry and anti-semitism during the crisis of the Black Death, where he exercised great charity defending the poor and the Jews. As a man, he lived a courtly life of great extravagance.

LeFanu's newly-commissioned score weaves together contemporary music with 14th century French polyphony and plainchant. The opera will showcase bass-baritone Nicholas Folwell as Clement and counter tenor Nicholas Clapton as the Flagellant leader/Novice master, alongside young singers and instrumentalists from the Royal Liverpool Philharmonic Orchestra's contemporary Ensemble 10:10, conducted by Clark Rundell, director of contemporary music at the Royal Northern College of Music, Manchester.

They will be joined by harpist Lucy Wakeford and percussionist Damien Harron. Clement as a boy will be played by Christopher Lakin, a chorister at York Minster, and another Minster chorister, Benedict Rowe, will play the altar boy.

This is LeFanu' s sixth opera. "The idea originated with tenor John Potter and writer/director John Edmonds," she says. "John Potter has done much work combining medieval and contemporary music with The Hilliard Ensemble and with his own group, Red Byrd. John Edmonds had written two previous scripts for these groups; it was an inspiration to use the life of Clement VI for Light Passing. I saw its dramatic potential and together we re-worked it into a chamber opera."

She considers Pope Clement VI to be "the most fascinating character". "He's a brilliant man living through turbulent times. He was remarkable for his tolerance, a generous patron of the arts and led the most sophisticated court at his wonderful palace in Avignon," she says.

"However, he was accused of being too worldly, too extravagant, and above all, of refusing to return the Papacy to Rome. To date there has been no portrayal of his life and I welcomed the challenge and opportunity of bringing him to life and in the process marrying together new music and music of the time."

LeFanu has researched the music that could have been sung in Avignon at that time. "Because Clement was crowned on Whit Sunday, I have been able to use the beautiful Whitsun plainchant hymns and the actual 14th century motet sung at his coronation. It is by Philippe de Vitry and I have incorporated other polyphonic pieces by him, as I discovered he was working in Avignon at that time," she says.

LeFanu welcomes the opportunity to work again with eminent contemporary conductor Clark Rundell, whose baton work has been in demand for world premieres of compositions by Django Bates, David Bedford and Richard Rodney Bennett. This will be his first world premiere of a LeFanu opera, although he has conducted several of her revivals, such as Dawnpath and The Story Of Mary O'Neill.

The libretto has been written by John Edmonds and directed by Cathy Denford, who worked with LeFanu in 1998 on the children's opera The Green Children.

Denford says: "The staging of this chamber opera in a medieval church is very appropriate. I will be making the maximum use of these wonderful surroundings. Light and darkness representing life and death will be key elements in the production. The richness and extravagance in Clement's life will be portrayed through vivid costumes; innovative use of moving light and shadow will highlight the dramatic action."

Tickets for the world premiere on October 28 cost £20 including drinks and canaps; tickets for October 29 and 30 are £10, concessions £8, students £3.50. All performances will start at 8pm, and bookings can be made on 01904 658338 or on-line at www.ncem.co.uk

Updated: 08:44 Friday, August 13, 2004