A Public Place of Amusement (PPA) License is required to produce, present or conduct any type of amusement. Venues charging an admission fee or accepting a donation for any type of entertainment or amusement requires a PPA license. Venues with a capacity of 100 or more people that offer any entertainment or amusement require a PPA, regaurdless if an admission fee is charged.
Chicago's Guide to Entertainment, Performing Arts & Theater Licensing