Their quiet generosity is hardly audible on the sidewalks of West Franklin Street in Chapel Hill, though they have a home base sitting in the Skills Development Center right across from the busy thoroughfare of restaurants and bars. The staff and volunteers of the Orange County Literacy Council do their work in all corners of the county, from spare campus classrooms to the extra office at an adult learner’s workplace. The OCLC’s annual fundraiser, Celebrate Diversity, features native author and musician Clyde Edgerton reading from his new book about flying, Solo: My Adventures in the Air, and performing two original songs. A silent auction and a raffle include a set of signed first editions of Edgerton’s books; a UNC basketball signed by Dean Smith, Bill Guthridge and Roy Williams; and the grand prize, a townhouse in Charleston during the Spoleto Arts Festival. Doors open at 4 p.m. on Sunday, Sept. 18 at the ArtsCenter in Carrboro, and admission is $20 (raffle tickets are $5 each or five for $20). For more info, visit www.orangeliteracy.org or call the ArtsCenter box office at 929-2787.