Movie music of a bygone era

Dallas Morning News: The American Film Institute's tribute to the 100 greatest songs in movies says a lot about America's lost innocence and short memory.
In a different era, movie theater audiences hummed and sang movie tunes. And it didn't much matter whether the lyrics were catchy and upbeat or dark and brooding. Theatergoers left darkened entertainment houses with a song in their heart ... and on their lips.
Times change
Oh, how things have changed. Except for music from animated features -- every 5-year-old knows every note from "The Lion King," "Finding Nemo" or "Shrek" -- the rest of us are clueless and tuneless. We aren't whistling away, unless, of course, our kids bombard us with a steady diet of Radio Disney movie tunes.
That's what makes the American Film Institute's tribute so endearing. Never mind that its selections are generally predictable and often cheesy. Nor does it matter whether we agree or disagree with their picks. ("Ben," an ode to a rat, wouldn't have made it on our ballot, that's for sure.)
The song titles rekindle memories long forgotten and, we hope, introduce a younger generation to past American culture. Is there anything more revealing about the mind-set of a generation than Depression-era movie music?
The music of the movies. What can be a more meaningful -- and melodic -- history lesson than that?