Greatest female singer ever?

I have so many that I love but I don't think anyone was as technically brilliant as this girl. She was flawless.

Aretha

Karen carpenter - superb singer, though not my kinda music...

Personal faves of mine would be Pat Benatar
Tiny woman - HUGE voice
https://www.youtube.com/watch?v=dsKCU5ll3D0
https://www.youtube.com/watch?v=ZInRE-KryGA
https://www.youtube.com/watch?v=7qUFZwJb9GA

And Kate Bush
https://www.youtube.com/watch?v=IfjPivYmV7Y
https://www.youtube.com/watch?v=BW3gKKiTvjs
https://www.youtube.com/watch?v=ot3cVY1JESQ
Watch and learn, Lady Gaga

Kate Bush is one of the all time greats. Love her voice and her songwriting abilities and yes, you're right, Gaga should take note.

Taylor Swift.

https://www.youtube.com/watch?v=nN6VR92V70M