"Benjamin Britten must be accepted as the most outstanding English composer working in the mid-20th century, winning a significant international reputation, while remaining thoroughly English in inspiration, a feat his immediate predecessors had been unable fully to achieve."
For the rest of this brief bio of Britten, visit here, his page at the Naxos website, or, for more information, you can go here, his page at Wikipedia.
Britten's A Ceremony of Carols has been familiar to me since my undergraduate days, though Britten also wrote several other compositions for choir or voice that are seasonally themed, such as Winter Words (based on the poetry of Thomas Hardy) for tenor accompanied by piano, and A Boy Was Born, for treble voices plus choir.
A Ceremony of Carols was written for treble voices, soloists, and harp. Britten took the text from a book of medieval poetry he stumbled across while stopping in Nova Scotia en route back to Britain after spending three years in the U.S. Some of the texts he set to music during his voyage, and the rest were completed by 1942. Any of the movements in it are worth a listen, but here are my favorites from the 12-song cycle, as sung by The Sixteen, under the direction of Harry Christophers, both on the CD, Hodie--an English Christmas Collection and in an mp3 collection, A Ceremony of Carols, Britten Choral Works II:
II. Wolcum Yule
III. There is No Rose
VI. As Dew in Aprille
VII. This Little Babe