Rock Music: 1951-1976 vs. 1977-2003

I think I understand the issue being discussed, but isn't this similar to: which came first, the chicken or the egg? If Muddy Waters and Howlin' Wolf hadn't done what they did, would the Beatles and Rolling Stones ever done what they did?
For the most part I think the phrase ' dwarves on the shoulders of giants' sums up the music world. How far back does one have to go to find the line between the dwarves and giants???
That said, there have been great musicians in every era, and to ask us to draw a line is a difficult and personal thing.
Comments were made about Jethro Tull for instance. I prefer some of their later work to their earliest work, but if it weren't for the early stuff the later stuff would never have been made!
I grew up in the 70's so it is all the more difficult for me to draw the line. The Doors work done in the early 70's I liked. The Jethro Tull and Bob Dylan of the mid to late 70's I prefered to the earlier work.
What came first, This Was or Crest of the Knave; Free wheelin' or Blood on the Tracks???
I personally prefer good music to era specific music!

Unclejeff...the 70s were the lowest point? Oh I would say the opposite. We had the most technical and melodic material of the times: ELP, Yes, Led Zep, Jethro Tull, Genesis, Pink Floyd, Rush, Beatles solo, etc., etc., etc. Much before with a few exceptions like Beatles, Stones, Moody Blues, rock bands were one-hit wonders. Fortunately many of these great bands continued into the 80s and even the 90s but so few new bands really came into play at the same level. What a disappointment! Once the 90s kicked in, the one-hit wonder phase returned. The 70s and even the 80s were times when I could put on an LP and enjoy both sides with perhaps all but one or two songs. Now with new material, I feel lucky to find more than a few songs worthy of my time.

There are a lot more rock bands post '77 than pre, but the quality seems more diluted? That's my perception anyways, but time has acted as a filter for me. Comparing a number of the best bands from pre and post, I'd say the differences in quality is too close to call. I like stuff from all the eras for various reasons (except early fifties).

Since I got involved with Frank Zappa when I was 15 the commercial world was going more far and far away from my listening tastes. Not knowing well English I swallowed FZ's well heard and pronounced lyrics and speaches during performances(BTW something to learn from PHD in English isn't it?) from his records and tapes and as far as time goes towards nowdays in such commercial-pop-free world everything becomes more interesting, sophisticated and creative. FZ-played musicians formed their own bands with smashing albums as well as members of Jethro Tull, Genesis, Yes, King Crimson, Can, ELP, Soft Machine, Roxy Music, etc.., merging with each other making such list is extreamly wide and rich that realy can compete with rest of commercial world and even wider, whilist pop and commercial stars light-up for a while and than everyone forgets about them or played and listened only by contemporary generation(s). Folks in 30-s will listen something from Abba or Tina Turner, Madonna; folks in 40-s will listen something as James Brown, Kool and the Gang; folks in 20-s will listen to Aqua, Back Street Boys etc...

You've got an interesting point. Contemporary artists are popular today. Only time will tell if they have lasting power. Meanwhile we sort of know who amongst the earlier artists have staying power. That's not to say many of them will a hundred years from now. But you and I don't care what happens a hundred years from now. It's what we enjoy today and tomorrow that's important. For me that's Wagner. He's got staying power ! Why ? Because his works are performed and the performers have the license to interpret his works so each production is different. We're not quite so flexible with Beatles of FZ or Christine Agulara numbers. Yet.