Christmas songs have been blasting out over the sound systems of shops over here in the UK for weeks now. They alternate between gratingly jolly seasonal jingles and, in slightly more upmarket shops, choirs of angelic voices retelling the Christmas story. The irony of this whole soundtrack to the festive system, and in particular of those carols proclaiming “no room at the inn,” is mostly lost on the customers thronging to fill their shopping bags with seasonal must-haves. The truth is there