Allow me to weigh in on the 60's v 70's discussion.
There was a time when I would have said the 60's because of disco and bloated prog rock in the 70's (Yes and Emerson Lake & Palmer I'm looking at you), but I've come to accept that disco was just an unfortunate (d)evolution of soul, R&B and motown. There was no excuse for ELP. On the bright side, both styles of music spawned punk and the diy era which was great.
TOM, the 60's were more significant but that was as much cultural as the music. And there was plenty of crap music in that decade too. The early 60's produced a lot of bubblegum rubbish and I'd argue that early Beatles was mostly shite. The mid-latter part of the decade certainly changed the course of popular music, but many of those musicians, the ones who survived became more proficient players in the 70's (i.e. The Stones).