An unforgettable live performance changed everything for one British band and became one of rock’s defining festival moments. Guitarist Alvin Lee of Ten Years After, tunes up before performing at Rose Palace, Pasadena, March 28, 1969.Mark Sullivan / Getty Images When Ten Years After arrived at Max Yasgur‘s 600-acre dairy farm in Bethel, New York, they were a hardworking British blues-rock band still building their audience.