Harold, I very much enjoy your post directly above. Nice to hear someone else give ABBA their due!
I imagine you know John Lennon loved "A Whiter Shade Of Pale", playing it incessantly they say. But I really must dispute you assertion that Gary Brooker and Hendrix "created the very first attempts to (write? create?) serious and important rock music". What do you consider "Like A Rolling Stone"? "God Only Knows"?
Leonard Berstein wrote, produced, and narrated a TV Special that aired on CBS in the spring of ’67, entitled Inside Pop---The Rock Revolution. One of the main segments is about Brian Wilson and his upcoming Smile album. Brian is shown playing "Surf’s Up" (lyrics by Van Dyke Parks, a much better lyricist that Brooker’s songwriting partner and Hendrix, imo) on the piano (yes, the one in the sandbox ;-) in his Bel Air mansion, and Berstein explains why he is so impressed. The show is viewable on You Tube.
To see and hear the genius of Brian Wilson explained and demonstrated, watch the You Tube video wherein a music teacher breaks down "God Only Knows", it's whole structure and construction. Chord by chord, the melody, harmonies, and counterpoint. It is mind blowingly great!