The biggest hit song of Crosby's career was his recording of Irving Berlin's White Christmas, which he introduced on a Christmas Day radio broadcast in 1941. (A copy of the recording from the radio program is owned by the estate of Bing Crosby and was loaned to CBS Sunday Morning for their December 25, 2011, program.) The song then appeared in his 1942 movie Holiday Inn. His record hit the charts on October 3, 1942, and rose to No. 1 on October 31, where it stayed for 11 weeks. A holiday perennial, the song was repeatedly re-released by Decca, charting another 16 times. It topped the charts again in 1945 and for a third time in January 1947. The song remains the bestselling single of all time.

According to Guinness World Records, his recording of "White Christmas" has sold over 100 million copies around the world, with at least 50 million sales as singles. His recording was so popular that he was obliged to re-record it in 1947 using the same musicians and backup singers; the original 1942 master had become damaged due to its frequent use in pressing additional singles. Though the two versions are similar, the 1947 recording is most familiar today.

After his death in 1977, the song was re-released and reached the No. 5 position in the UK Singles Chart in December 1977. Crosby was dismissive of his role in the song's success, saying "a jackdaw with a cleft palate could have sung it successfully."

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