From July 22 through August 31, 2008, Groff played the lead role of Claude in the Shakespeare in the Park production of "Hair", a rock musical about hippie counterculture during the Vietnam War that was directed by Diane Paulus. Theater critic Ben Brantley of "The New York Times" wrote in his review of "Hair" that "Mr. Groff, who was memorably tormented by young lust in the musical 'Spring Awakening,' is even more affecting here, his open face a shifting map of doubt and affirmation." Groff decided to turn down the opportunity to reprise his role in the Broadway production, choosing instead to make his film debut"." In 2009, he appeared as Michael Lang in Ang Lee's comedy-drama film "Taking Woodstock", about the 1969 Woodstock Festival. While critics found the film "likable" but "underwhelming", Groff's performance was praised for its "crafty, angelic fervor" by "Rolling Stone".