In case anybody else is interested in learning the whole song from the music in Indiana that Jim Dixon linked for us, I am convinced that the first measure of the song (not the intro) is written wrong.

I tried and tried to sing it off the sheet music, and I just couldn't get it memorized, because it sounded so unnatural. Then one day my fingers took the law into their own hands and changed two notes. Tada! A perfectly reasonable-sounding first phrase.

The printer printed this: F D F D Db C

My fingers went for: F D F D D C#

I might sing it at the singaround.