Written and first performed by Joni Mitchell (1969).
Hit versions by Crosby, Stills, Nash & Young (US #11 1970), Matthew’s Southern Comfort (US #23/UK #1/CAN #5/IRE #2/POL #2/SWE #2 1970).
From the wiki: “‘Woodstock’ was written by Joni Mitchell and included on her 1970 album Ladies of the Canyon. But, was first performed Mitchell at the Big Sur Folk Festival in September 1969, one month after the Woodstock Music and Art Festival. The song was notably covered by both Matthews Southern Comfort, and by Crosby, Stills, Nash & Young and would on to become a counterculture anthem. Mitchell wrote the song from what she had heard from then-boyfriend, Graham Nash, about the Woodstock concert. She had not been there herself; she had been told by a manager that it would be more advantageous for her to appear at the time on The Dick Cavett Show. Mitchell wrote it in a hotel room in New York City, watching televised reports of the festival.