The festival is also remembered for the first large-scale public appearance of Janis Joplin.
It's also regarded as one of the beginnings of the "Summer of Love". That event became the inspiration and template for future music festivals, like Woodstock, two years later.
In 1970 an album was released titled Historic Performances Recorded at the Monterey International Pop Festival. Included on the album are sets by Otis Redding and Hendrix.
Another famous festival from the 60s was the Newport Folk Festival. First held in 1959 in Newport, Rhode Island, it's often considered as one of the first modern music festival in America. At the 1965 festival, Bob Dylan famously performed with his Fender Stratocaster electric guitar and did a version of his song Maggie's Farm. It was not received well by the audience with many booing.
There are many albums recorded at the festival including a two volume set, released in 1960 titled The Newport Folk Festival.
One of the most famous festivals from 1969, for all the wrong reasons, was the Altamont Speedway Free Festival held on December 6, 1969, at the Altamont Speedway in Northern California. The concert featured appearances by Santana, Jefferson Airplane, The Flying Burrito Brothers and the Rolling Stones.
Sadly the event is best known for considerable violence and the stabbing and subsequent death of one of the festival attendees. There were also three other, accidental deaths at the concert, two caused by a hit and run car accident and one by an overdose of LSD.
The stabbing happened while the Rolling Stones were performing. The Hells Angels biker gang was handling security for the concert and one over-exuberant concert-goer tried to storm the stage and was grabbed by security and hauled back into the crowd. It was after that initial skirmish that things got ugly and the stabbing occurred.
Filmmakers Albert and David Maysles shot footage of the event and incorporated it into the 1970 documentary film, Gimmie Shelter.
There certainly are many more music festival that have had a major influence on modern music.