Blending American folk harmonies with British-invasion psychedelia, the Byrds burst onto the international rock scene in 1965 with hits like “Mr. Tambourine Man” and “Turn, Turn, Turn.” After several years of superstardom and another hit track, the unabashedly pro-drug opus “Eight Miles High,” the group’s lead songwriter, Gene Clark, quit the band. (Ironically, he claimed his primary reason for doing so was his fear of flying.) Though he would occasionally re-join the band over the years, the Byrds never recovered creatively from Clark’s departure. Set You Free: Gene Clark in the Byrds 1964 – 1973, due early January, is a robust box set with a focus on their body of work produced with the aid of Clark’s inspired touch.