@wolfie62 has noted:
LINDA RONSTADT
She has more range and has SUCCESSFULLY recorded more styles of music than most of these fine ladies put together.
The fact that she sold more copies than most of them (the modern ones have a larger audience and streaming, etc.) isn’t really germane.
She can actually SING.
You should also read her first book, "Simple Dreams" where she writes that she can LISTEN to most any (beginning) singer and identify the singer(s) they are copying. THAT, friends, is talent in my estimation. (The album of the same name ain’t bad either, FYI.) Finally, her version of a superb Smokey Robinson song (Ooo, Baby, Baby) is my favorite, and I would NEVER denigrate Smokey, who is one of a kind as well.
Also, hard to beat Joan Baez singing "Diamonds and Rust" on a good pair of Maggies with quality ARC gear driving them.
Cheers!