On June 4, 1976, four young men took the stage of the Lesser Free Trade Hall in Manchester and, in front of a handful of people, played one of the most important live sets of all time. Alongside Woodstock and Live Aid, the Sex Pistols' performance has been named by critics as one of the most pivotal performances in music history...not necessarily because of the quality of the music - but because of the effect the music had on the audience. The crowd were mesmerized by the power and possibilities of punk - and it inspired them to create their own music that would shape the sound of rock music for decades to come. Members of Joy Division and New Order, the Smiths, the Fall and Buzzcocks were there that night as well as Tony Wilson, a key player in the story of Factory records, the Hacienda, Madchester and beyond. This was truly a gig that changed the world. The truth behind that gig - plus the Pistols' repeat performance six weeks later and their first ever TV appearance - has been shrouded in mystery for thirty years. Until now, everyone's been happy to print the legend. For the first time, here's the truth. Featuring previously unpublished photos, interviews with key players and audience members, "I Swear I Was There" brings pop culture to life thirty years after the Summer of Punk.