how old were you when Sergeant Pepper came out? Were you even alive? If not, you have no way of appreciating how revolutionary The Beatles music was. During the time that almost every song on rock radio was either a blues or a 1 6 4 5 progression, “I wanna hold your hand“ changed keys three times. By the time we got to their later work, they were doing things with orchestration and harmony,that no one had ever done in rock.. Everyone else has now assimilated all of their innovations so they seem common place today, but at the time they were revolutionary.