What Is Genuinely Musically "Avante-Garde"?

The only validation I've gotten within conventional
classical music that I've found re my work with
12TET all-interval-class/all-contour melodies is
in the cello introduction to Rimsky-Korsakov's
Scheherezade (which is a melody using five 12TET
intervals), and that was written in 1888.

Bill Flavell