This is the 'a capella' version of Alexander L'Estrange's beautiful mixed voice composition, Lute-book Lullaby. First performed by the choir Tenebrae, directed by Nigel Short, who also commissioned the work, it was first performed on 12th September 2002, at St Luke's, Chelsea, London at a concert in support of Downs Syndrome.
The piece can be found on the Signum Records CD Mother and Child (SIGCD501) performed by Tenebrae and Nigel Short.