For anybody under 30 (or maybe even 40), it must feel as if God wrote "White Christmas" on the eighth day of Creation - right after He took a quick rest and cranked out "Silent Night." But, like everything else, "White Christmas" really does have a story - an unusual story, so it turns out.

The movie to watch every December is not the leaden "White Christmas" from 1954, but rather the hokey but still appealing "Holiday Inn" from 1942. Despite one offensive number with star Bing Crosby in blackface, what matters is that the movie features Crosby and Fred Astaire, two of the greatest performers of the 20th century; has a score by Irving Berlin, our greatest songwriter; and introduces one of the two or three most important songs ever written. Is there anyone between Portland and Portland who can't sing all the words, verse excepted, to "White Christmas"? About a half hour into the movie, Bing sits at a piano in a snowbound country inn and begins to croon, "I'm dreaming of a white Christmas...."

There are several contradictory stories about how Berlin wrote the song, and it's hard to know exactly which facts are true. What's clear, though, is that he did not write it for the movie. In fact, he probably wrote it four years earlier. The most romantic version of its composition says that he wrote it while working in Hollywood, unable to get home for the holiday. So what? He was Jewish. But his wife was Roman Catholic, and he had become very fond of Christmas. Perhaps feeling a little sorry for himself, the insomniac songwriter stayed up all night to finish it before calling his secretary in the morning, "Grab your pen and take down this song. I just wrote the best song I've ever written - hell, I just wrote the best song that anybody's ever written!"

Ironically, a pretty ballad called "Be Careful, It's My Heart" was supposed to be the big hit from "Holiday Inn," but the public, and especially men in combat on Guadalcanal, embraced "White Christmas," intuiting its melancholy appeal when World War II was just about a year old - during the first Christmas season when large numbers of Americans were apart and in peril. The song's conjuring up of childhood memories and idyllic New England winters transformed it into a comforting vision of home for Americans frightened and bewildered by the fears and dangers of wartime. When Berlin realized that circumstance had changed "White Christmas" from a holiday song into a war song (or what he preferred to call "a peace song"), he gave orders to drop its verse from the sheet music. No more lines like "the orange and palm trees sway" and no more references to "Beverly Hills." Berlin was also a very canny businessman.

Today, as we stand around a piano, bellowing out "Deck the Halls" and "God Rest Ye, Merry Gentlemen" and then "White Christmas," we're far removed from the loneliness and fear of those who heard the song when it was new. Despite its idyllic imagery, the song's melancholy melody touched a deep emotional chord, and still does for those who truly listen. The lyric has someone writing on a Christmas card, "May your days be merry and bright / And may all your Christmases be white." The wishes are genuine, but what's missing is any promise of return. It is as upbeat as a song without hope can be.

Crosby's recording was a million-copy seller in 1942-43, and since then has sold upward of 130 million copies, but during the song's initial burst of popularity, both Frank Sinatra and Freddy Martin's well-known dance orchestra also had million-copy recordings. To this day, Crosby's version adds an additional 100,000 copies to its total every year. "White Christmas" also inspired a number of other deeply felt songs during the war years that became Christmas standards, including "I'll Be Home for Christmas," "Have Yourself a Merry Little Christmas," and "The Christmas Song," also known as "Chestnuts Roasting on an Open Fire."

Americans have always celebrated two Christmases. One celebrates the birth of Christ, the other the coming of Santa Claus, the decorating of trees, and the gathering of families. Irving Berlin's simple song has nothing to do with religious belief; it is the great anthem of America's secular Christmas. An anthem does more than sing about its subject; somehow it illuminates, elevates, and embodies it so that subject and song become one. No one had a keener feel for what Americans believed, knew, remembered, hoped, and dreamed than Irving Berlin. In songs like "God Bless America," "Alexander's Ragtime Band," and, of course, "White Christmas," the immigrant songwriter spoke for all of us. His was a quintessential American story. As "White Christmas" demonstrates, if it was on America's mind or in America's heart, it soon found its way into a song by Irving Berlin.