S.S.
I teach music classes at Wonderworks a museum in Oak Park, not far from certain parts of Chicago. They are not as expensive as some of the others. Also, every single day, beginning on June 1 or June 3 until September 1, in Millenium park at 10 am there are wiggle worms (music) teachers performing for 45 minutes and then there is an art tent right next door. All free, every day and other fun things there to do!
good luck