Answer
The iconic music festival that Cass Elliot famously performed at was none other than Woodstock. Held in August 1969 on a dairy farm in Bethel, New York, this legendary event witnessed an astounding turnout of nearly half a million people. Over four days of peace, love, and music, Elliot mesmerized the vast audience with her exceptional talent, making her performance an unforgettable highlight of this cultural phenomenon.