• During the 1970s, rock music diffused into every corner of the music industry.
• Rock completed the transformation from an experimentalist, countercultural movement into a profit-making center of the American entertainment industry.
• Rock music’s characteristic expression of tension between commercialism and authenticity emerged in a clear form during the 1970s.
• The 1970s saw the first appearance of rock ’n’ roll nostalgia, a sign that (1) the baby boomers were aging and (2) rock music had begun to develop a sense of its own history.