well his voice was great up to 72' and at the 73' concerts it was just waaaaaaaay over used adn really hoarse and scratchy. But sonce there wasnt any tours in 74', buy 75' his voice was mosty healed and he sounded great(like earls court shows) and by 77' the same 73' incident happened again...It most likely had something to do with his 75' car accident though. After his son died in 77' he had almost 2 years to heal it up again, so he sounded really good at the knebworth 79' shows....and that was almost basically the end, cause of the death of john bonham in 80' and some solo stuff i dont like, but his newest album mighty rearranger i really like, and at the concert last summer he sounded fantastic! So anyways, my whole point is, Robert has always been a great vocalist, probably the best in my opinion. And I forgot to add one little thought, a lot of people forget that your voice does change with age and im guessing matures as you become older. When Rob started singing back in 66' he was only 18 years old, and when zep started he was 20, and I dont know for sure, but 20 is still pretty young, and i think he probably still had a little more growing up to do w/ his voice, and thats why it changed so much over the years, putting so much stress on it as he was still trying to develop it.
Well, those are my thoughts..sometimes i get a little carried away with my zeppelin-ness
