How has rock as a genre evolved over the years?!

How has rock as a genre evolved over the years?

It started off almost as good as it ever got with the golden oldies, Chuck Berry, Bo Diddly, Elvis, the usual suspects. That hit it's climax in the fifities sometime and it kind of slowed down a little, 'til the early 60's, at which point British bands like the Rolling Stones and the Kinks and American bands like The Wailers and The Sonics kicked up an entirely new generation of energetic youth that became the garage rock and psychadelic era, which was, although not totally, mostly an American movement. That's not a rule though because across the seas there were great bands like the Troggs, The Pretty Things, The Easybeats etc. This scene was extremely vital and raucous and great up until abooout '67 or so, at which point the energy started to fade and huge multitudes of new bands stopped popping up everywhere. There was also plenty of pop/rock during those periods but they aren't as important in this discussion. '67 ended up being a critical juncture, two albums came up that basically showed which two distinct directions rock was travelling in, first in March came the Velvet Underground & Nico, keeping the vitality of the previous eras with new unique experiments and darker themes. The other came later in June and was called Sgt. Pepper's Lonely Hearts Club Band and had a lot more studio experimentation and added effects. This eventually led to prog rock and an endless amout of big headed, ridiculously long "Look how good I can play" guitar solos and concept albums that put even the best of bands in a bad place. This part of rock history bores me so I'm not going to talk about it or it's most famous bands, Yes, ELO, Genesis, Led Zeppelin etc. etc.

The other route fronted by by the Velvets and their hard rockin' cohorts, expanded even further on their second album a year later in '68, took us into post garage and glam rock like the Flamin' Groovies, The Stooges, T.Rex, Bowie, and the New York Dolls. We call these protopunk bands in retrospect because they all had that raw, simple, straightforward, occasionally aggresive sound that would be championed by the punks of the mid to late seventies. By now in the early seventies though the prog rockers had completely overshadowed these great bands except for the occasional hit like "Get It On" by T.Rex and some by Sweet and Slade and Bowie and the like, mainly in the UK. So a new generation of kids grew up that had taken the Stooges and Velvets to heart and rather abhorred the boring guitar solos and cocept albums, so they formed bands like Television and the Patti Smith Group and the Modern Lovers which had more in common with the Velvets, and others formed bands like the Dictators, the Ramones, the Heartbreakers (with Johnny Thunders not Tom Petty) and the Sex Pistols which owed much more to the raucous abrasive sound of the Stooges. Then these bands inspired their peers in turn and (more so in the UK again) bands started springing up all over the world that wanted to revive and revitalize rock 'n' roll, and this was the '77 punk explosion. This answer is too long, so suffice it to say that this inspired post-punk and hardcore in the late seventies and 80's, which inspired post-hardcore/emo/alternative in the late 80's and grunge/indie/more alternative in the 90's and a hell of a lot or revivalists of the early days in the 00's. Keep in mind this is subjective and purely off the top of my head which means I skipped a lot on accident and a lot more on purpose (no one cares about 80's synth-pop right?). So there's my very abbreviated version and you will find about a billion conflicting ones everywhere you look, no one quite agrees. But I've never been wrong before.