The song's original working title was "Uncomparable", however, the music publishing company asked Gordon to change it to "Unforgettable".

The most popular version of the song was recorded by Nat King Cole, in 1951, from his album, Unforgettable (1952), with an arrangement written by Nelson Riddle.

[3] A non-orchestrated version of the song, recorded in 1952, is featured as one of the seven bonus tracks on Cole's 1998 CD reissue of 1955's otherwise completely instrumental album, Penthouse Serenade.

Natalie Cole had been performing this duet using a recorded track in her live show through the 1980s,[4] then in 1991, after Elvis Presley's musical director Joe Guercio had the idea, Cole's original 1951 recording of the song was edited and reworked to create a duet with his daughter, Natalie.

[15] Billboard commented, "Through the magic of digital technology father and daughter duet on this timeless song that swells with lush orchestration and moving harmonies.