THE OLDER I GET…
The older I get, the more I appreciate the ability to be happy—which is a habit of mind as much it is good fortune or a momentary, pleasant mood. So, say, when I was a teenager, I idolized “Lady Day,” whose blues gave sanction to my own suburban tristia. Now, while I still love Billie Holliday, I find profound comfort in Ella, for instance, whose manifest joy in performance buoys me every time I hear her.
WordRustler 
I agree, the ability to be happy is important and something to strive for. As for Ella and Billie, I’d say that Billie has more soul but Ella is more professional and has a better voice. It’s all about how I feel on any given day.