Avoiding the usual summer-concert fare, the Grant Park Music Festival presents a slate of mostly American contemporary music, beginning with Barbara Kolb’s 1993 All in Good Time. The oldest work on the program is Szymanowski’s Violin Concerto no. 1, from 1916: its lushness evokes Debussy, its chattering echoes Stravinsky. This isn’t an ego-gratifying piece for the soloist, who has to work for every scrap of glory, battling the orchestra almost the entire way before slipping out at the end on a soft high note. Here the soloist will be Glen Ellyn native Jennifer Koh, a graceful communicator with a sweeping lyrical sound and marvelous bow control. Two darker works will end the concert: Inspired by 9/11, Aaron Jay Kernis expanded the instrumentation of a movement from his second string quartet to create Sarabanda in Memoriam. Michael Hersch’s Ashes of Memory predates the terrorist attacks, but with its deafening first movement and somber second, it could be a fitting commemoration. Carlos Kalmar conducts. Free. Thursday and Friday, July 1 and 2, 6:30 PM, Harris Theater for Music and Dance, 205 E. Randolph; 312-742-4763.