Julie Andrews ~ The Sound of Music ~ The Lonely Goatherd
http://www.youtube.com/watch?v=fQEhMbKJJko
Audrey Hepburn ~ My Fair Lady ~ I Could Have Danced All Night
http://www.youtube.com/watch?v=SDUaPgAcfb0
Julie Andrews ~ I Could Have Danced All Night
http://www.youtube.com/watch?v=JNaIor5lxN8
As to I Could Have Danced All Night, that was actually sung by Marni Nixon.