The principals went on to form The Orchestral Society of Illinois in June 1988 which first performed in March 1991 as "Symphony II" under the leadership of Larry Rachleff who was the orchestra's artistic director until May 2013.
[2] In 2012 the organization, led by its new Board Chairman Paul R. Judy, also began a transition to its formal and unique structure as a musician-governed society supported by an active membership of musicians and non-musicians.
[3] The orchestra has maintained a partnership with Ravinia Festival for over 20 years and has served as a resident company at the Harris Theater for Music and Dance at Millennium Park in downtown Chicago since 2016.
[9] The basic principle that guides the structure of the organization is: "The Society is most effective at achieving its musical aims when informed and controlled by musicians.
[6] They have performed with artists including Joshua Bell, the Los Angeles Master Chorale, Lady Gaga, Tony Bennett, Johnny Mathis and Third Coast Percussion.
[12] Other performances in the 2018–2019 season include Weill's Suite from The Threepenny Opera, Ravel's Piano Concerto in G Major, Harbison's Remembering Gatsby, Gershwin's Rhapsody in Blue, Tchaikovsky's Romeo and Juliet Overture, Daugherty's Raise the Roof, Rimsky-Korsakov's Scheherazade, as well as live musical accompaniment to films Sherlock Jr., Fadeaway with Koko the Clown and Sure-Locked Homes with Felix the Cat and a collaboration with Cirque de la Symphonie.