"A Festival of Nine Lessons and Carols is the Christmas Eve Service held in King's College Chapel at the University of Cambridge. The Festival was introduced in 1918 to become a more imaginative approach to worship." lt was firsat broadcast in 1928 and has since become a global tradition and is broadcast to millions of people around the world." I well recall listening to the serene sound from far and distant Canada.
"The service includes carols and readings from the Bible. The opening carol is always 'Once in Royal David's City'" Source: http://www.youtube.com/watch?v=NMGMV-fujUY&feature=related