The Summer Jam at Watkins Glen was a 1973 rock festival which once received the Guinness Book of World Records entry for "Largest audience at a pop festival." An estimated 600,000 rock fans came to the Watkins Glen Grand Prix Raceway outside of Watkins Glen, New York on July 28, 1973, to see the Allman Brothers Band, Grateful Dead and The Band perform.Thousands of music fans abandoned their cars on state highways worried that they would miss the opening of Summer Jam. With the chaos of Woodstock still fresh in the memory, tickets for Summer Jam were limited to 150,000 by organisers. Like Woodstock, many ticketless fans showed up anyway. About 600,000 – roughly one person in every 350 in America at the time - went to witness music history being made, causing one the biggest roadblocks America had known.By the time the bands had packed up and the crowds had dispersed, newspapers were reporting four road deaths, 50 arrests and the birth of one child.Although the line up for Summer Jam was big on talent, the $10 ticket promised just three acts. Sadly, some of the recordings of the performances at Summer Jam were never released, which perhaps explains why memories have faded about its occurrence. Nonetheless, Rick Danko, a vocalist in the Band, spoke fondly of the event, saying: "Woodstock, Isle of Wight and Watkins Glen - those were the big three for us."(Photos by Grant Gouldon , via The Guardian