[left that other site]

The songs from that era often had those clever little intros, very few of which are sung today.

[Publius]

Even “God Bless America” had an intro when Irving Berlin wrote it in 1917 for his Army review, “Yip Yip Yaphank”. I heard the intro done at Yankee Stadium a few years ago during the 7th inning stretch at a World Series game.