This past August 15, 16, 17, and 18 was the 50th anniversary of the 1969 Woodstock Festival, officially named “An Aquarian Exposition: 3 Days of Peace and Music,” created by the four-headed, at-cross-purposed, producing team of Michael Lang, Artie Kornfield, John P. Roberts, and Joel Rosenman.   But despite all its pre-production difficulties, its mounds of personality discord, and its fields of endless garbage that the iconic festival paid to have hauled away, “Woodstock” also earned its reputation as the era-defining event of the 1960s counter culture, the moment in time when music, culture, and history all came together to be…