The original lyric to "Have Yourself a Merry Little Christmas," which I learned about after happening to catch the tail end of "Meet Me in St. Louis" while channel surfing last night. We happened to drop in just as Judy Garland was about to sing the much-loved Christmas tune, which might have been less-loved if Judy hadn't pushed for happier lyrics. The line, revised, is "Let your heart be light/Next year all our troubles will be out of sight."
What Judy and Margaret O'Brien are so sad about there is moving to New York. They love St. Louis.
Judy's version, in turn, was insufficiently happy for Frank Sinatra, who got the line "Until then we'll have to muddle through somehow" changed to "Hang a shining star upon the highest bough." Here's Frank. I think "muddle through" would have suited him — that edge of sadness. And "bough" is a silly word.
There's another place in the song with alternate lyrics: "Through the years, we all will be together if the fates allow," was originally "if the Lord allows." Judy sang "the fates," but returning to "the Lord" is something you can always do.