Calendar, your search has ended--right where it began.
As long as artists like X and Bruce Springsteen are considered "radical," rock 'n' roll is the term you need.
As readers have pointed out before, most of what Calendar writes about is lyrics, not music. There is something called New Music out there; it's chronicled in John Schaefer's "New Sounds." And it's created by artists like Mike Oldfield, David Sylvian and Peter Bardens, who have gone beyond the boundaries of rock 'n' roll.