Condition: the phrase must have been coined for the song.
It cannot be a pre-existing expression that has become more widespread through song.
This joke appeared in a book of Knock Knock jokes I once had. The year was around 1979:
Sam and Janet.
Sam and Janet who?
I didn’t get it, so I told it to my mum, who laughed out loud.
Oscar Hammerstein II is the only lyricist I know whose work features in a rapidly obsolescing knock-knock joke.