Ya, they'd definitely mess around with each of the middle sections.
Stage 1: Bass intro and wah-wah interludes
Stage 2: Main vocal theme
Stage 3: Fast instrumental and 'oriental' riffs
Stage 4: "San Francisco/Achilles Last Stand" or "Woodstock"
Stage 5: Violin bow episode including echo-slapping from the guitar; interlude with Plant's 'instrumental voice'; Gustav Holst's Mars, the Bringer of War and return of the rhythm section
Stage 6: Fast guitar solo and battle with Plant
Stage 7: Slower tempo solo and 'funky' moods
Stage 8: Violent breaks and call and response interlude
Stage 9: Faster solo in crescendos and occasional break-up tempo, some occasions combined with "Walter's Walk" or "St. Tristan's Sword"
Stage 10: New arrangement of Mars, the Bringer of War (slow and fast versions) and final frenzy
Stage 11: Return to main theme
Stage 12: Coda. Final instrumental and vocal battle inside syncopated rhythms, drum-solo and final explosion.
Longest version ever was at the LA Forum in 1975. Clocked in at just over 45 minutes
