The classic 2003 Will Ferrell film “Elf” got crammed into a B’way musical 2010. It didn’t get better. But it gave us an okay song about Christmas singing “A Christmas Song” here star-powered by Jim Parsons and Kate Micucci from the 2014 TV special (quaintsy and quirky) as opposed to Sebastian Arcelus and Amy Spanger from the original cast recording below (more chorus, more from the diaphragm).