Betty is a "personality" performer. She was an emotive performer, not a perfectionist. She "felt" her songs and took you along, I love that about her though it can be overwhelming at times.
This is a beautiful song, period, no matter who sings it! Some songs are just fantastic, and this is one song that truely is a fantastic song! I was not born until later, from when this song was made; it's not in my generation, yet I love it!
I'm shocked that anyone can listen to this and find Betty's voice lacking. She has a fantastic voice. She was one of the best big band singers ever and became one of the best entertainers in movies. Her tone is gorgeous.