I think that one of the problems that jazz has is that it's so incestuous that it's starting to kill itself.
Music and fashion have had a kind of incestuous relationship since the Fifties. It started with people like Elvis Presley and pop icons like James Dean. Then it exploded in the MTV days. Now, with the Internet, it's instantaneous.
Sexual desires rather than communal and historical sensitivities would then define the marital relationship, ... allowing such combinations as three-party marriages, incestuous marriages, child brides and other less-than-desirable couplings.
The intimate, even incestuous Circle in the Square where the audience was close enough to be patrons of the saloon.