Collutorium . . . strange name. It denotes an a capella group of singers, founded in 1996 by doctors from the Radcliffe Infirmary to raise money for local charities. Perhaps the medical connection explains that name - actually the Latin for mouthwash - which they hope signals a refreshing experience.

Will Orr, one of the founders, still conducts the choir, leading it on its tenth anniversary concert on Sunday - in Keble Chapel where it was first performed. That soaring structure, painted and decorated to awesome effect, has an echo to rival King's and might seem intimidating. Not to these singers, though they did field a strong string of bass voices to keep them grounded while the sopranos and tenors took off.

The recital also included two groups of pieces, by Gabrieli and Scarlatti, for brass (two trumpets and three trombones) which seemed perfectly suited to the acoustic and flamboyance of the place. I'm not usually a brass fan, but these were splendidly bright and stimulating. Almost all the choral music was sung in Latin. The opening piece, however, also performed at Keble in 1997, was Aaron Copland's ambitious setting of the Genesis story In the Beginning, with soprano Susan Young. Here the soloist proclaims God's words while the choir provides continuity ("the evening and the morning . . ."), musical colour like the stirring waves and waters, the brilliant light and the final coda "a living soul".

Works by two contemporary Americans, Morten Lauridsen and Eric Whitacre, continued the meditative, liturgical theme. Lauridsen set traditional texts O magnum mysterium and Ubi caritas et amor - a complex contrapuntal structure. Whitacre's Lux, in its commissioned Latin, made much use of the high voices to suggest light.

At intervals came motets by Bruckner, his meditation on the sacred Name swelling and using that echo to the full, and, in the Sacerdos magnus, the Great Priest, reinforced by the brass instruments and the organ, giving us that whacking great authentic Bruckner sound.

Follow that, you might think. Will Orr followed it with Whitacre's Sleep, a strange piece, part naive Robert Louis Stevenson quatrains, part dark echoes of "What dreams may come". The composer explains that the music had been intended to set a poem by Robert Frost which was barred by copyright and so a new text was tailored to fit. The result, despite a clever final diminuendo on sleep', seemed rather tame. They're a good group though. I shall watch out for them again.