Adorno was an ultimate non-conformist, and felt music should change the world in some way, should be intelligent and decisive and independent. I think what he loved about music was that it needn't follow society's rules, or anyone's rules. And he found, with modern music, that music didn't even have to follow music's rules. Being free of these confinements, music could be autonomous, and exist on its own; and the more autonomous it could be, the truer and more important, to music, it became.
Breaking all the rules, and seeking contradictions, produces musical dissonance, and in that sound lay reflections of society, according to Adorno. It could make a true and profound statement. Unrest, harsh truth, need for change - contradictions in society, as in the music. An autonomous art reflecting social truth.
I think this is why more conforming music was troubling and unappealing for him. Having less autonomy, this music became less important and less skilled, and reflected only conformism. He found that boring, and worse, it said something sad and negative about society to him, like music had let him down.
Can music affect societal change?
Is there something valid in Adorno's point that you don't even have to be paying attention to popular music to listen to it? Is that unfortunate for us as listeners, for society, for musical culture?