Tenderly, Love For Sale, Summertime, Laura, Round Midnight; those are songs somebody wrote. They've been around for ages, and played by jazz musicians, popular musicians, rock musicians, and possibly even country and western musicians. A person can go to school, practice, and perfect his skills on his chosen musical instrument, learn how to play all of those songs perfectly in his chosen musical style; but none of that will enable a person to write one of those songs.
No amount of practice, school or many other musical attributes will enable a musician to mesmerize a crowd of people with his improvisational skills on his chosen instrument night after night. "Only" jazz musicians can do this, and not all of them; it's a gift that's reserved for those who are recognized as being at the very highest pinnacle of musicianship, Charles "Yardbird" Parker for example.
One step down from this pinnacle, are the musicians who have successfully led groups of other musicians over the years and written music as well; Horace Silver, Thelonius Monk, Dave Brubeck, and Art Blakey come to mind. And last on this ladder of success are musicians who have simply excelled on their chosen instrument. Since this group is so arbitrary, I won't give any examples because there is too much disagreement as to how we should rank them overall as jazz musicians.
If a "jazz" musician can excel on his chosen instrument, and play someone else's music better than it's ever been played before, that's fine; but it drops him down a notch if he can't create "original" music of his own that excels in the ears of other "jazz" musicians and aficionados.
Fame and fortune might be the determining factors in other endeavors, and music even; but not in "jazz". If that were the case, Kenny G would be "Da man". Unlike any and everything else, the high priests of jazz are determined by aficionados and other jazz musicians. Charles "Yardbird" Parker, the recognized high priest of jazz, was relatively poverty stricken.
While it's almost impossible to compare current and past jazz musicians because of the generational gap, one of the most important factors is the stability of current musicians who also reject drugs and alcohol. That certainly helps their economic success. "Jazz" musicians are still rated the same way now, as they were when "Bird" was blowing his horn, they're rated by other jazz musicians and jazz aficionados, not by Newsweek, Time, or MSNBC. Jazz is the only anything, where the unofficial word on the street is the last word.
"They've had no real experience with the real essence of those guys (Miles, Trane and Monk) -- the way they help their instruments, the way they acted, what really caused this music. Most of the cats trying to play hardcore contemporary jazz don't have their own style. Or there are some people like Wynton [Marsalis] who play the horn, but don't play no hip jazz. They're just into playing the instrument good. They're not creating ideas." That was a quote from Freddie Hubbard and my own personal opinion as well. His statement and my opinion have absolutely nothing personall to do with Wynton Marsalis, that's just the way it is.
Enjoy the music.