Billie or Ella? Maria or Renata? Technique or feeling?

Ella -straight ahead "Jazz"

But, tylermunns, the same can be said of practically every instrumentalist that played this music.  So, you’re saying that all those great instrumentalists that played, for instance, “All The Things You Are” were not playing Jazz at all?  That all those great performances of “three minute pop tunes” that served as vehicles for Jazz improvisation were not Jazz at all?  Not arguing, just trying to understand your  viewpoint.  Getting back to singers, please name other singers besides Lincoln that you consider to truly be Jazz singers.

In the meantime, how about a little non-Jazz 😉:
 

@frogman 

"For me an even more interesting question is why, when considering artists in the admittedly very small group at the very top level of excellence, some listeners feel the need to declare one or the other “the best” as if that opinion is some sort of objective truth".

Well, we all have egos. One thing I've noticed about mine-- it 's very enamored of trying to (objectively) "validate" it's subjective preferences,  Of course, this is an impossible quest but that doesn't stop it trying!  :o)

It's only because I recognize this in myself that I recognize it in others. It's so very "human". 

@tylermunns 

"As far as vocalists go, Ella isn’t “straight jazz.”  When we talk of vocalists of this ilk, (Holiday, Vaughn, Washington, Sinatra, etc.) I don’t consider any of them “straight jazz.” I think of Abbey Lincoln who, by the 1960s, was singing real-deal jazz music with the great Max Roach (her husband).  Brilliant.

Those previously mentioned vocalists are singing the songs of Jerome Kern, Cole Porter, the Gershwins, Harold Arlen, Rodgers & Hart, Irving Berlin, Rodgers & Hammerstein, etc.  "

I hope I misunderstand but you seem to be asserting in the above post that when Jazz musicians play/sing tunes written by Jazz musicians, they are Jazz artists but once they tackle "songbook" material, they suddenly (in your mind) morph into something suspect-- something lesser-- something somehow not quite "legit".    What are they, then. at such moments-- Pop artists? Coltrane playing Naima is Jazz but Coltrane playing "My Favorite Things" is Pop?  

"When I think of jazz vocalists, I think of people singing jazz music"

Judging whether something is Jazz solely based upon the origins of the material seems to me a very distorted perspective.  

Have you considered why "My Funny Valentine", "All The Things You Are", etc. have been interpreted many many times and in many different ways by "straight' Jazz players? Perhaps there is something about these tunes that lend themselves to exploration via a Jazz esthetic that makes them valued by Jazz musicians? 

Betty Carter is a supreme example of an artist who took "standards" and truly made them her own. If you don't recognize that as the very essence of Jazz, you and I, Sir, hail from very different planets. 

"Jazz is a way of playing music."  ---   Jelly Roll Morton. (he should know)

Which means all of the first Jazz tunes, were not Jazz, when written, but played in a Jazz style later.

Cheers

@rok2id 

"Jazz is a way of playing music."  ---   Jelly Roll Morton. (he should know)

Which means all of the first Jazz tunes, were not Jazz, when written, but played in a Jazz style later"

Yes! This is exactly what I was attempting to convey!