The funny thing is that, as concerts go, Woodstock is usually considered very overrated. It's the sense of nostalgia and its place in pop culture - along with Altamont - that kinda signaled the end of the idealism that characterized the late-1960s.
You can look at festivals like Monterey Pop, Glastonbury, or the Isle of Wight and they produced a lot more interesting music (often with the same bands) than what went on at Woodstock.