Out of the albums that you mentioned, which would you say are the least structured?
San Francisco, probably, or rather the bonus album therein.
But plenty of stuff on those in your list is pretty structured (Dolphy and Tyner for one, and Ornette's c major music, too, really).
Donauseschingen certainly is a good suggestion, too!
I don't see "lack of structure" as a point of interest, rather how structure (or form) is used, how tradition is being expanded and stretched into new areas (which is maybe why "Mama Too Tight" is my favourite Shepp, you can hear Ellington in there ... and which is why ultimately I prefer Mingus or Dolphy or Ornette to, say, Charles Gayle, Frank Wright and others that are more on the berserk end of the spectrum.
As for "the more dissonant ..." - different genre, but try some Phill Niblock (make sure no animals are harmed, though).
At the present time, a lack of traditional structure and consonance is not only a point of interest for me, it's my primary interest. I'm currently interested in hearing the least traditional, least structured offerings in each artist's catalog. I'm less interested in hearing a representative sampling of Artie Shepp's work than I am in hearing his least structured albums.