Leave it to the good people at Wikipedia to tell us (as Paul Harvey would say) “the rest of the story” behind the Irving Berlin classic that will forever be associated with Bing Crosby.
The first public performance of the song was by Bing Crosby, on his NBC radio show The Kraft Music Hall on Christmas Day, 1941. He subsequently recorded the song with the John Scott Trotter Orchestra and the Ken Darby Singers and Chorus for Decca Records in just 18 minutes on May 29, 1942, and it was released on July 30 as part of an album of six 78-rpm discs from the musical filmHoliday Inn. At first, Crosby did not see anything special about the song. He just said “I don’t think we have any problems with that one, Irving.” The song established and solidified the fact that there could be commercially successful secular Christmas songs— in this case, written by a Jewish-American songwriter, who also wrote “God Bless America.” The song initially performed poorly and was overshadowed by Holiday Inn‘s first hit song: “Be Careful, It’s My Heart”. By the end of October 1942, “White Christmas” topped the Your Hit Parade chart. It remained in that position until well into the new year. It has often been noted that the mix of melancholy — “just like the ones I used to know” — with comforting images of home — “where the treetops glisten” — resonated especially strongly with listeners during World War II. A few weeks after the attacks on Pearl Harbor, Crosby introduced “White Christmas” on a Christmas Day broadcast.The Armed Forces Network was flooded with requests for the song. The recording is noted for Crosby’s whistling during the second chorus. …In Holiday Inn, the composition won the Academy Award for Best Original Song in 1942. In the film, Crosby sings “White Christmas” as a duet with actress Marjorie Reynolds, though her voice was dubbed by Martha Mears. This now-familiar scene was not the moviemakers’ initial plan. In the script as originally conceived, Reynolds, not Crosby, would sing the song. The song would feature in another Crosby film, the 1954 musical White Christmas. White Christmas became the highest-grossing film of 1954.
You can read more here.
Also notable is the opening lyric, which is almost never heard:
The sun is shining, the grass is green, The orange and palm trees sway. There’s never been such a day in Beverly Hills, L.A. But it’s December the twenty-fourth,— And I am longing to be up North—
And below, the original version of the classic, from “Holiday Inn.” Merry Christmas, one and all.