How Little We Know

"How Little We Know" is a song written by written by Hoagy Carmichael and Johnny Mercer for the 1944 film To Have and Have Not, where it is performed by the character "Slim" played by Lauren Bacall. A young Andy Williams recorded the song for the film as a possible alternative track to dub Bacall's low voice. Bacall said they used her singing. After the film's release it was a hit recording sung by Judy Johnson.

It has been covered periodically, most recently in 1999 by Michael Feinstein with the Maynard Ferguson Big Band.

...
Wikipedia