If you missed hearing the 2015 Service of Nine Lessons and Carols live on Christmas Eve, you can catch a replay on BBC Radio 3 on Christmas Day at 9 AM US Eastern time; or you can replay it over the net from the website of BBC Radio 4 at your convenience; the program will be available until January 22 (approximately).
Information on the service is available on-line, including a program booklet with details of the readings and the musical selections.
I note a decided shift at King's College to a more contemporary form of the service in the choice of readings and in a number of fairly recent compositions–almost all by the late and great choir Director Sir David Willcocks. In Catholic settings you might find the use of incense with Benediction at the conclusion, or at the Magnificat , or more readings from the sermons of the Greek and Latin Fathers in parish celebrations of this singular expression of the Christmas season. Now, almost as common as the Advent wreath.
Given the acoustics and the beauty of King Henry VI's chapel, I can see why this celebration of nine carols and nine lessons becomes increasingly popular each Christmas with hundreds of millions of listeners and viewers in over 120 countries. A broadcast going back to 1928 forever traditional and like all good liturgy forever changing to the tempo and tastes of the times.
Thank heavens they have kept "In the Bleak Midwinter." I've been seduced by the "Darke side!"