<P> The Grateful Dead toured constantly throughout their career, playing more than 2,300 concerts . They promoted a sense of community among their fans, who became known as "Deadheads", many of whom followed their tours for months or years on end . In their early career, the band also dedicated their time and talents to their community, the Haight - Ashbury area of San Francisco, making available free food, lodging, music, and health care to all . It has been said that the band performed "more free concerts than any band in the history of music". </P> <P> With the exception of 1975, when the band was on hiatus and played only four concerts together, the Grateful Dead performed many concerts every year, from their formation in April 1965, until July 9, 1995 . Initially all their shows were in California, principally in the San Francisco Bay Area and in or near Los Angeles . They also performed, in 1965 and 1966, with Ken Kesey and the Merry Pranksters, as the house band for the Acid Tests . They toured nationally starting in June 1967 (their first foray to New York), with a few detours to Canada, Europe and three nights at the Great Pyramid of Giza in Egypt in 1978 . They appeared at the Monterey Pop Festival in 1967, the Woodstock Festival in 1969 and the Festival Express train tour across Canada in 1970 . They were scheduled to appear as the final act at the infamous Altamont Free Concert on December 6, 1969 after the Rolling Stones but withdrew after security concerns . "That's the way things went at Altamont--so badly that the Grateful Dead, prime organizers and movers of the festival, didn't even get to play," staff at Rolling Stone magazine wrote in a detailed narrative on the event" </P> <P> Their first UK performance was at the Hollywood Music Festival in 1970 . Their largest concert audience came in 1973 when they played, along with the Allman Brothers Band and the Band, before an estimated 600,000 people at the Summer Jam at Watkins Glen . The 1998 edition of the Guinness Book of World Records recognized them with a listing under the heading, "most rock concerts performed" (2,318 concerts). They played to an estimated total of 25 million people, more than any other band, with audiences of up to 80,000 attending a single show . Many of these concerts were preserved in the band's tape vault, and several dozen have since been released on CD and as downloads . The Dead were known for the tremendous variation in their setlists from night to night--the list of songs documented to have been played by the band exceeds 500 . The band has released four concert videos under the name View from the Vault . </P> <P> In the 1990s, the Grateful Dead earned a total of $285 million in revenue from their concert tours, the second - highest during the 1990s, with the Rolling Stones earning the most . This figure is representative of tour revenue through 1995, as touring stopped after the death of Jerry Garcia . </P>

How many songs did the grateful dead play