In 1975, a Junior Youth Symphony was added to included string students with less musical experience.
In 1990, AYS began holding their annual Fall and Spring Concerts at Hatheway Hall on the campus of Lewis and Clark Community College in Godfrey, Illinois, all of which are free of charge.
In 2004, the Alton Youth Symphony Chamber Ensemble was started with a single string quartet of AYS members. It has since grown into an ensemble that travels around the community to perform at various events.
AYS is governed by a fifteen member volunteer board of directors that is comprised of interested citizens from the community. The board includes active and retired music educators, parents of members, and members of the local business community.
Alton Youth Symphony alumni have gone on to become music educators, performers, members of the Alton Symphony Orchestra, and the St. Louis Youth Symphony, as well as other performing ensembles throughout the world.