It had been three years since the group was in Milwaukee and rock music has taken some strange twists and turns since then. Some very good rock groups have compromised their musical integrity by selling their souls to gimmicks, gadgets and the foibles of a few loud and abusive fans. But Led Zeppelin was as true to its music as it was the last time around. Led Zeppelin never forgot what it was there for – to play the sometimes sweet, sometimes sour hard rock that has kept it on top while others have come and gone.