Thanks for locating the whole song, Jim. I suspected there was an introduction, and you found it. Hoagy Carmichael came from Indiana.

This tune is a challenge. It has a range of an octave plus a third. And the chords - Ab mi 7, any one?

I recall hearing this song on television as a kid, and they always blasted it good and loud, with trap drum going and maybe a couple of trumpets. But it seems to me a song which should be sung gently, caressing all those chromatics.
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It's fun to look at the list of songs also published by the same firm (page 5) and to see which of them are familiar to me.

Deep in the heart of Texas
Tico Tico
You're nobody till somebody loves you
Wabash Cannonball, among others.