This is a link, from YouTube, to one of the most beautiful recordings ever made. It is of Ella Fitzgerald, singing "Someone to Watch Over Me," from the 1950 album
Ella Sings Gershwin.
She is accompanied by the wonderful pianist Ellis Larkins.
https://www.youtube.com/watch?v=IBSjLFJBW6M
http://en.wikipedia.org/wiki/Ella_Sings_Gershwin