There's something about being in a church and hearing massed youth choirs and guitar-on-the-knee folk music against a backdrop of jazz grooviness that makes me think of Ned Flanders from The Simpsons. And the London premiere of Harvey Brough's multi- idiomatic mass Requiem in Blue certainly inspired such unruly intrusions. With its repetitive melody, it felt more concerned with communal uplift than musical invention, but Brough's ambitious project was a moving affair for many extra-musical reasons.

There was plenty of musical emotion in the pre-Requiem parts of the show too, with performances from Brough, his remarkable vocal partner Jacqui Dankworth, and the dynamic gospel-influenced jazz singer Liane Carroll. Dankworth's delicate control and rich, low sounds were even more effective in the erratic, but sometimes highly supportive acoustics of the Union Chapel. Brough, whose bell-like voice makes him sound as if he would be equally at home in a folk club or cathedral, sang an early English folk song, while Carroll delivered The Nearness of You with her usual aplomb.

Three reflective pieces from Dankworth and Brough's regular group Field of Blue provided some of the evening's most transporting moments, particularly on the haunting blues Don't Really Care. Requiem in Blue was preceded by a powerful reading by Ben Okri on themes of cultural collision and the meaning of freedom. The youth choirs of the Islington Music Centre and City of London School then gathered for the Requiem, a constantly shifting mix of elements: Latin mass, Gregorian chanting, freewheeling jazz-flugelhorn flights, percussion duets, blues and folk.

The musical ideas rarely took you somewhere you didn't expect to be, but the collective exuberance brought a big inner smile, and the spiralling drama of the last movement, a prayer for redemption composed by Lee Hall, was a tour de force.