Rock music has had a massive effect on society. Just look at the 60-70's to confirm this. Styles of clothing, Beliefs, cliques, etc. have been formed from rock influence. Rock has had a tremendous effect on the "counter culture". It's been used politically, religiously and emotionally to convey one's beliefs, which others relate to.
Just pick an era and look at the trends which were active in said era. Do you think goth's (example) would really have such similiar principles, dress, and way of life without music? They form their "style" around the goth look. Which is influenced by gothic type bands and lyrics.
Pick a trend, and most can easily be linked to a genre of music.
My thoughts only.
