1. The music was new and different every day.
2. Music and politics were tied in a new way.
I'll debate (and win the debate, thank you!) on point 1 later. Here's what I mean by #2:
Musicians have always been listening to and commenting on politics. But in the '60s the synergy really came to a head. We had the urban folk scene, long politically aware, drift toward and eventually merge with the new and changing rock sensibility, and new things were being said and sung about daily.
Clearly one of the seminal figures at the nexus of folk, politics, and rock was a kid from Minnesota named Bob Zimmerman. He wrote stuff like this:
Come senators, congressmen
Please heed the call
Don't stand in the doorway
Don't block up the hall
For he that gets hurt
Will be he who has stalled
There's a battle outside
And it is ragin'.
It'll soon shake your windows
And rattle your walls
For the times they are a-changin'.
Indeed. Relevant much? Can you say FISA?
Here's Bob singing this song: