By the mid-1950s Britten had established himself as a major composer, both of operas and of works for mixed professional and amateur forces – his mini-opera "The Little Sweep" (1949) was written for young audiences, and used child performers. He had previously adapted text from the Chester play cycle in his 1952 "Canticle II", which retells the story of Abraham and Isaac. "Noye's Fludde" was composed as a project for television; to the Chester text Britten added three congregational hymns, the Greek prayer "Kyrie eleison" as a children's chant, and an "Alleluia" chorus. A large children's chorus represents the pairs of animals who march into and out of the ark, and proceedings are directed by the spoken Voice of God. Of the solo sung roles, only the parts of Noye (Noah) and his wife were written to be sung by professionals; the remaining roles are for child and adolescent performers. A small professional ensemble underpins the mainly amateur orchestra which contains numerous unconventional instruments to provide particular musical effects; bugle fanfares for the animals, handbell chimes for the rainbow, and various improvisations to replicate musically the sounds of a storm.