Why does the Grey Mary return each year? And who really went a-wassailing? In the fifth of seven daily programmes Sir Geraint looks at the local carol customs which survived down the centuries. In Cornwall the male voice choirs of the mining regions sing their own Christmas hymns; Wales has both old winter festivities and a unique kind of carol; Somerset and Yorkshire are among the areas where the wassail bowl was filled. Today's carols: 'Now the holly bears a berry', 'Here we come a-wassailing', 'Lo, he comes an infant stranger', 'The Mari Lwyd ceremony song', 'The Drayton wassail'.