John Tavener, British composer
b. 1944, d. November 12, 2013, age 69;
after chronic health problems including two heart attacks and Marfan's disease.
http://en.wikipedia.org/wiki/John_TavenerBest known for choral works including 'Song for Athene,' written in 1993 for a family friend killed at a young age in an accident, and sung at the funeral of Princess Diana in 1997.
http://en.wikipedia.org/wiki/Song_for_AtheneIf you don't have a CD, it's worth buying one; Westminster Abbey, St. John's College Cambridge, or the Sixteen would all probably be good. There's an audio sample on the Wiki page, or perhaps you video fans will link a clip.
Another often-sung anthem is 'The Lamb,' a modern setting of the famous poem by William Blake ('Little lamb, who made thee?'), now occasionally included on Christmas choral CDs.
(Not to be confused with the Renaissance composer John Taverner,
http://en.wikipedia.org/wiki/John_Taverner , c. 1490–1545. I always have to double-check.)