Since their first collaboration in 1969, Crosby, Stills and Nash have been credited as one of the first “super groups.” The founding members of The Byrds, Buffalo Springfield and The Hollies together became voices of the Woodstock generation with their anti-war anthems and entrancing harmonies. Crosby, Stills and Nash play PNC Bank Arts Center Aug. 19 and the Nikon at Jones Beach Theater Aug. 20, sans occasional band mate Neil Young. Classics like “Long Time Gone,” “Almost Cut My Hair,” and “Just A Song Before I Go” are sure to be revisited. Tickets start at $20.75.