Ray has been an inmate at the Louisiana State Maximum Security Penitentiary, known as Angola Prison, for more than 30 years. On the verge of signing a record deal, Ray committed a crime that would bring him a life sentence in Angola, which was once considered one of the bloodiest prisons in the country. His story is a prominent part of Music From the Big House, a documentary that follows Canadian blues legend Rita Chiarelli as she earns rare access to Angola and its musically inclined inmates. The film follows the blues singer in a concert created through collaboration with prisoners. Denton’s Thin Line Fall Series presents the documentary at 7 p.m. Saturday at the Fine Arts Theatre, 114 N. Elm St. on the Square. Tickets cost $8, available at http://thinlinefilmfest.tix.com .