Never work with children, they say. The Oxford Bach Choir ignored this maxim at its summer concert last weekend, and was very nearly upstaged by the combined choirs of Pegasus School and St Nicholas School, Abingdon. This delightful ensemble of children, all primary school age, sang a selection of Spanish songs with extraordinary musicality, impressing the Sheldonian audience with their enthusiasm, tunefulness and purity of tone, not to mention some slick, well-coordinated actions. Their contribution - which included popular numbers such as Rio Grande and Y Viva Espagna - was undoubtedly a highlight of the evening.

Another highlight, for me, was the wonderful Misa Criolla by Argentinean composer Ariel Ramirez, whose setting of the Mass is based on traditional folk tunes, rhythms and instruments of South America, and combines a sense of fun with a proper spirit of reverence. The singers (pictured as it ended) were clearly enjoying themselves, and delivered the piece with precision, flair and a great sense of style, ably backed by the Percussion Ensemble from the Royal Welsh College of Music and Drama. The solo soprano line was well sustained by Jennifer Walker, although some of her top notes would have benefited from a more rounded sound.

No such problems, though, for Welsh baritone Owen Webb, whose rendition of Vaughan Williams's Five Mystical Songs was masterful, combining some lovely, lyrical phrasing with a velvety-rich voice. Superb.

Stanford's Magnificat was a chance for the choir to demonstrate their ability to sing a capella, which they did with apparent ease, while coping with the intensity of the work and the demands of singing as a double choir.

The evening was brought to a lively conclusion by Constant Lambert's Rio Grande, an eclectic piece that combines the styles of the classical piano concerto, the English choral tradition and 1920s jazz. Once again, the choir was backed by an impressive contribution from the Percussion Ensemble, and some very skilful, well-sustained virtuoso passages from pianist Steven Kings.