"Celebration at Big Sur"

[Kammass]

Needing some help, 
I purchased a movie poster off ebay "Celebration at Big Sur" and don't know 
anything about it.  Can anyone help?  Its a, 1971, movie and it says 
"Celebrate with: Joan Baez, CSN&Y, Joni Mitchell, John Sebastian, and 
introducing Dorothy Morrison". (don't know her at all!)     
Thanks, 
Kammy

NP= Ben Harper-Welcome to the Cruel World