There was a lot of artists all pulling in different directions. Only the creativity was common to all of them.
Some of it was begun earlier than 65 but..
There was certainly a backlash against pop music singles. That had not happened before. Not with Rock & Roll it didnt. Part of that was the blues rediscovery, and some of it was out & out experimentation with song forms and music forms.
In terms of the electric guitar it was an almost blessed period. The analog distortion amazed people. It wasnt 'really' new, but it was appreciated as a new sound, instead of shunned as unwelcome distortion. It was a bit like MSG: you sprinkled it on everything and it made everything taste good.
Now we simulate those sounds digitally and most of the time get it wrong. We instinctively go for more distortion and then wonder why it is only other metal players that are listening.
But I digress. I loved King Crimson & Pink Floyd at this time. Especially Floyd. I really thought that the title track 'Saucerful of Secrets' was pointing to the future.
Also, as Frank Zappa identified, record companies didnt understand what was going on, so almost anyone was given a chance, and those that did were allowed to indulge themselves (if they insisted!).
Ever heard the track 'Saucerful of Secrets? Can you imagine this being permitted for inclusion on a release by a young band today?
Can you imagine the reception Bob Dylan would get on The X Factor?
Even on here at SS we try hard to fit into well tried moulds established many years ago.