I don’t think this song needs much of an introduction–here’s “White Christmas” by Irving Berlin, sung by Bing Crosby and Martha Mears (dubbing actress Marjorie Reynolds), in the movie Holiday Inn:
Video posted by alpineic1. (Only the first two and half minutes or so of the video are from the film.)
Or, if you prefer, a cover by Bette Midler that includes the rarely-recorded first verse:
Video posted by Bette Midler – Topic, provided to YouTube by Sony Music Entertainment
Or there’s this:
The song was written for the aforementioned Bing Crosby/Fred Astaire vehicle Holiday Inn and became an instant classic. Crosby’s version of “White Christmas” is the best selling record of all time,* the single selling at least 50 million copies; when all the various covers (over 500 at current reckoning) are taken into account, the song is estimated to have sold over 150 million copies and there has even been an entire book written about it. All this despite–or perhaps because of?–the fact that it’s not so much about Christmas itself as, as the lyrics tell us, a dream or fantasy of what an ideal Christmas ought to be.
* Since the Crosby’s single was released before singles charts were a thing, I’m going by the conclusions of the researchers at the Guiness Book of World Records.