Sir Geraint looks at the way carols were rediscovered in the 19th century, from the clerics who chanced upon a Latin text containing many now-famous carols, to folk song collectors Cecil Sharp and Ralph Vaughan Williams. Today's carols: 'Good King Wenceslas', 'Unto us is born a Son', '0 little town of Bethlehem', 'It came upon the midnight clear', 'The voice of God is heard above', 'Morning star O cheering sight'.