The proggy, bluesy “In My Time of Dying,” slinking along on the back of some of Jimmy Page’s greasiest slide-guitar work, stretches past 11 minutes, shifting from a deathly crawl to a raucous double-time romp. The extended format means the band can indulge every whim and include experiments that might have been harder to justify on a single disc. And the odds-and-ends feel of Physical Graffiti is one of its strengths, showing every side of Led Zeppelin in a single sprawling package. Tracks like the crunching “Houses of the Holy” (intended as the title track for their 1973 album) and the loose and lyrical “Down By the Seaside” (written in 1970 and reworked for the group’s fourth record, but ultimately not included) may have been meant for other projects, but they easily meet the band's exacting standards. While each of those first five records was created during a concentrated period of recording, much of the sixth, the double LP Physical Graffiti, drew from material developed at earlier sessions. Led Zeppelin were on a tear in the early part of their career, releasing a streak of riff-driven albums between 19 that set a new standard in hard rock.
