The Illinois Symphony Orchestra is central Illinois’ largest professional orchestra serving over 35,000 patrons in the communities of Bloomington-Normal, Springfield and the surrounding region with symphony orchestra, chamber orchestra, and Concerts for Kids series in each community. In addition to concert performances, the Orchestra's music education and outreach programs serve pre-K and elementary schools through the Itsy Arts and Music Matters education programs and reach middle schools, high schools, universities, community organizations and senior centers through guest artist residencies and musician and ensemble performances. The ISO also has an active Around the Town Chamber Music Series and virtual Sunday at Six Recital Series. The Illinois Symphony Orchestra has a budget of approximately $1.3 million.
In July 2020, the ISO acquired the Sangamon Valley Youth Symphony (SVYS) organization that was started in the early 1970s by parents, music teachers and musicians to keep string programs and youth orchestra in Springfield and surrounding communities following the elimination of all school orchestra programs. Now, the Illinois Symphony Youth Orchestras (ISYO) programs consist of Starter and Junior Strings, Preparatory Orchestra, Concert Orchestra and Symphony Orchestra serving over 150 students. The ISO also has a partnership in education and community engagement (PEACE) with the UIS-School of Music and Illinois State University’s Wonsook Kim College of Fine Arts and School of Music.