Prior to 1963, the music played in the 1960s closely reflected the sound, style, and beliefs of the preceding decades. After 1963, many social influences changed what people considered popular music. The Kennedy assassination, the war in Vietnam, and the civil rights movement all had a huge impact on the mood of American culture and the way music began to reflect the change. The "British Invasion" was a period in which many British bands and artists came to the United States and performed extremely well. The most famous of these groups was "The Beetles", who would eventually go down in history as one of the most famous groups in history. During the height of the music industry in the 1960s, a single event changed American music forever. Woodstock was a three-day concert full of sex, drugs and lots of hippies. Organizers expected around 50,000 people to attend. To their surprise, more than 400,000 people showed up at the infamous New York dairy farm. With artists like Jimi Hendrix and Bob Dylan, many have been drawn to this phenomenon. This festival is widely known as the watershed moment for the greatest generation of counterculture. The 60s radically revolutionized music in a way that made music the driving force it is for generations.