premise: But you have to admire Merrill's  Any old Alley opportunist can write a novelty Italian song (That's Amore) or a novelty mambo song (Papa Loves Mambo), but to write a novelty song about Italians doing the mambo--that takes 
hypothesis: You don't have to admire that Merrill's Any old Alley opportunist can write a novelty Italian song--it's a very simple thing to do.