I too attended that festival. If I remember correctly, it was called "Strawberry Fields" and was a year to the weekend after Woodstock.  The crowd was huge and pretty weird, as I recall seeing 2 guys in white robes with "staffs" and beards and they pretty well freaked me out.
I don't remember alot of the acts, but I remember "Melannie" was first, did a great version of "Candles in the Rain" and Jethro Tull played that first night and Alice Cooper was making his debut of sorts. I remember them dressed in women's closing and being so outrageous.  Beyond that, my memory is foggy.  I think "Sea Train" played, maybe Procul Harum. The years have dimmed my memory a bit. Any insights?