Led Zeppelin was a band that when they played well, they were the best in the world, mostly in the first years, somewhat in 1973, but after 1973, quite a few performances were good as earlier concerts. Plant's voice during 1975 was quite hard to listen to and sometimes very embarrassing. The 1980 tour was unnecessary, I think Zeppelin came to their creative end in the 80's even without John Bonham's death. Plant's voice was far cry from glory days in 1971 and In Through the Out door was not a great album. Also, they should did rehearsal for at least week in 1985 for Live Aid, come clean and tried to be as good as Queen, without Phil Collins, same thing for the MSG in 1988. In many ways Zeppelin was inconsistent band, without middle ground, they were like gods at good nights, or deeply embarrassing on bad nights.