Child choristers have been singing at Salisbury for 900 years. This film - an observational portrait, history and musical immersion in one of Britain's most distinctive and beloved cultural traditions - follows Salisbury Cathedral's choristers over Easter and through the summer term of 2011. Salisbury Cathedral's separate boy and girl choirs each contain 16 of the most musically gifted eight- to 13-year-olds in the country. Their role, now as always, is to sing some of the most sublime music ever written in one of Britain's most beautiful buildings. Indeed there are many who believe the chorister's pure, clear, treble voice is the finest instrument in all music.