I'm a big fan of Amy Winehouse, back when I had to get my stewardess friends to buy copies of her album because it wasn't released stateside.
But legend?
Jawn had 2 albums.
Amazing singer, amazing voice, a lost talent...but that's about as far as I'd go.
She definitely had more vocal range than Billie, but contraltos by default have more vocal range.
You're right about Amy - she's playing in a box that Billie built. Same goes for Badu, later Mary J Blige, about 40,000 others.
I'm hard pressed to think of any female singer who could possibly compete with what Billie does. She revolutionized what you could do with a song.


"Your current frequencies of understanding outweigh that which has been given for you to understand." Saul Williams