Golda Schultz sings Barber’s Knoxville: Summer of 1915 — a haunting evocation of childhood memories — plus arias by Stravinsky and Carlisle Floyd. Alongside these, Kwamé Ryan conducts music by two quintessential American iconoclasts: Charles Ives’s The Unanswered Question and a new concerto by George Lewis, featuring the piano-and-percussion quartet Yarn/Wire.