Amazon.com essential recordingThis 1975 release came smack in the middle of a long and nearly mythic career. Physical Graffiti is the last great Led Zeppelin title, recorded before the influences of the day (synthesizers, disco) ended Zeppelin's reign as the kings of loud and sexy blues-metal. Playfully experimenting with new sounds, the band blended Middle Eastern rhythms, folk-stylings, heavy blues, and deeply impassioned rock riffs into a two-disc set that sounded as if they were still enjoying their place in the rock pantheon. As sprawling and adventurous as this collection is, there are some tracks so tightly focused--so ultra-Zeppelinesque--that it's tempting to name this as a number one or number two must-have. "Trampled Underfoot" and "Custard Pie" alone are almost worth the double-disc price tag. --Lorry Fleming