Hi,
Having lived through the 60's in Brazil and Madison, Wisconsin and then the 70's in Santa Barbara, CA .... makes for one thing ... really different experience and music ...
So it may come to a shock to you when I would like to make a recomendation of a couple of books to read ... and not because it is "progressive" but because it has a view ... that is way more descriptive and explorative of the musical scenes in various places ... it is also a very good commentary on some "people" ... and it did for me the one thing that really helps the most when discussing and describing these things ... it takes out the "star" content ... and it takes out the "progressive" whatever ... and it takes out the "rock" content ... and it takes out the ... whatever content ...
And what you have left is people ... and their creativity ...
If you ever have the chance read Pamela Des Barres first two books ... I'm one with the band, and then the follow up to it ... if anything, it puts a "real face" in the music scenes in LA and SF that we often consider hippy, progressive and whatever other labels ...
And in the end, there is one other thing that you will gain from here ... and it is about Frank and Gail Zappa ... and I won't say any more ...