"Christmas (Baby Please Come Home)" is a song by Darlene Love from the 1963 Christmas compilation album, A Christmas Gift for You from Phil Spector. The song was written by Phil Spector, along with Jeff Barry and Ellie Greenwich, with the intentions of being sung by Ronnie Spector of The Ronettes. According to Darlene Love, Ronnie Spector was not able to put as much emotion into the song as needed, so Love was brought into the studio to record the song instead, which eventually became a big success.
Darlene Love has performed the song on the final new episode of the Late Show with David Letterman before Christmas every year, since 1986 (previous to 1994, the performances were on NBC). The song is always performed with the Late Show's house band, the CBS Orchestra, augmented by additional strings and other instruments, as well as a full choir.
No one does this like Darlene—the 1981 performance is the first time (I believe) she performed the song after she sued Phil Spector for royalties. Enjoy.