By Denny Dyroff, Staff Writer, The Times Quinn Sullivan and Buddy Guy Guitar ace Quinn Sullivan is headlining a show on June 22 at the Sellersville Theater (24 West Temple Avenue, Sellersville, 215-257-5808, www.st94.com) and will be performing dates with blues legend Buddy Guy later this summer. Three weeks ago, Sullivan was sitting in class as a student at New Bedford High School in Massachusetts.