The store owner sees him looking at the sign and says "He sings Christmas Carols."
"Well, he's not singing anything now."
"You have to warm up his feet. Watch." He pulls out a Zippo and holds it under Chet's right foot and Chet bursts into song:
o/~ Jingle Bells, Jingle Bells, Jingle all the way... Oh what fun it is to ride o/~
But he stops the moment the owner pulls away the lighter. The owner grins at Bill and puts the lighter under Chet's left foot:
o/~ Deck the halls with boughs of holly, falalalala la la la la. o/~
Again, he stops when the lighter is taken away. Bill asks the owner if he can try it and takes the lighter and repeats what the owner did, with the same results. He's pretty amazed at this point. "Well, what happens if you put it under both legs?"
"I don't know, never tried it," the owner replies. And when Bill tries it, Chet bursts into a new song:
o/~ Chet's nuts roasting over an open fire... o/~