Songfacts®:

• This was written by Irving Gordon, who wrote a lot of comedic and parody songs. Some other songs he wrote include "What Will I Tell My Heart" (recorded by Bing Crosby), "Me, Myself And I" (recorded by Billie Holiday) and "Mama From The Train" (recorded by Patti Page).
• Nat King Cole recorded this with orchestra leader and arranger Nelson Riddle in 1951. It became a hit again in 1991 (US #14, UK #19) for Nat's daughter, Natalie, when her vocals were dubbed with his to make a duet.
  
  Her version was included on her album Unforgettable: With Love, which contains other tributes to her father as well, as she also recorded "Mona Lisa," "Nature Boy" and "Route 66." Natalie's version of the song won Grammy Awards for Record of the Year, Song of the Year, Best Traditional Pop Performance, and Best Instrumental Arrangement Accompanying Vocal (for Johnny Mandel). The Song of the Year award went to Irving Gordon 40 years after he'd written it.
  
  The album also won for Album of the Year and Best Engineered Album - Non-Classical.
• Nat King Cole was biggest seller for Capitol Records for much of the late '40s and early '50s. He did a lot of work with Nelson Riddle at Capitol, but "Unforgettable" was the first session where Riddle got an official credit for his arrangement. The two continued to work together, with Riddle doing orchestrations for The Nat King Cole Show, a variety show Cole hosted in 1956 that was the first of its kind starring a black man. Riddle also did a lot of work with Frank Sinatra when he joined Capitol in 1953.
• Natalie Cole overcame a wild seesaw of a career with dizzying heights and terrifying lows. When she was a mere six years old she was performing on Christmas albums with her superstar dad, and by the '70s she was churning out her own hits in the R&B genre, including the very successful "This Will Be (An Everlasting Love)." Natalie was still in her 20s when she developed a crippling drug addiction and hit a career ebb for nearly a decade. Her fortunes revived in the late '80s, and in 1991, at age 41, she had her greatest success with the Unforgettable...with Love album.
  
  Health issues plagued Cole; she contracted hepatitis C as a result of her drug use, had a kidney transplant in 2009, and died of congestive heart failure in 2015 at age 65.
• This song's 1991 revival came at an unlikely time, as grunge and gangsta rap were the big trends, and an album of jazz standards seemed like the perfect way to keep a contemporary artist off the charts. Cole's album, and this song in particular, proved a welcome alternative to the popular music of the time, especially with older listeners with no interest in Pearl Jam or Dr. Dre. Many of these listeners were Grammy voters, which helped considerably at awards time. The album led to many other modern artists recording standards album, including Rod Stewart, Cyndi Lauper and Robbie Williams.
• There is a bit of irony in Natalie Cole recording her father's songs to such acclaim. She made an effort to stay away from singing so she wouldn't face the expectations of being Nat King Cole's daughter. When she started performing a bit her senior year in college, she realized that the talent and determination were there, but she made sure to perform in a different style than her dad, singing rock and funk instead of crooning ballads. She successfully distanced herself from her dad and achieved her goal of making it in her own right, but as she got older, she got more comfortable being Nat King Cole's daughter and was determined to record his songs.
• The 2002 album When Pigs Fly: Songs You Never Thought You'd Hear featured a version of this song recorded by action film star Jackie Chan and folk singer Ani DiFranco. Cevin Soling, who put the album together, explained to Songfacts: "The Jackie Chan/Ani DiFranco duet was pretty trippy. Ani recorded her part in Buffalo, and Jackie recorded out in Hong Kong, and I brought the tracks that Ani had recorded in Buffalo out to Hong Kong. I guess I was a little surprised, because Jackie does all these films, I kind of expected his English to be a little better than it is. And his English is okay, but there were a few places where he was stumbling, and it turned into me singing the lines to Jackie and him singing them back to me - you can imagine how surreal that is. So that was a blast, getting time in China, and also getting to spend time with Jackie Chan, and he was really sweet. He arrived a bit early, and he had a body guard, which I thought was a bit funny. There was something really funny about him having a body guard, but his body guard had a broken arm or wrist or something. One of his arms was in a sling. So that was all kind of strange and surreal in and of itself. He had just come from some Save The Panda rally and was very involved in a lot of causes, and he was expressing his frustration over the newspapers only being sensational and not discussing the causes and things that he cares a lot about. So he was very earnest that way. But the man is like made of granite. If you were to hit him you would really hurt yourself. He was just solid. It would be like punching a mountain. And yet he's still unbelievably flexible.
  
  There's a good friend of mine, her name's Jen White, and those were her two idols. She was just in love with Jackie Chan and Ani DiFranco, and so it was sort of a dare kind of thing. It kind of came from the idea, how funny it would be if I could hang out with both of her idols and put them together and do this thing."
• Australian singer-songwriter Sia covered this as the end-credit song for Disney-Pixar's Finding Dory. The movie's director Andrew Stanton said: "In the same way Robbie Williams did his own unique twist on a classic song for Finding Nemo, Sia captures the soulful truth of the Nat King Cole classic 'Unforgettable,' and makes it all her own. They are a perfect complement to one another, just like the two films."