R.P.
Lisa - there are Thur night concerts in the Rochester Municipal Park - usually at least one is kid oriented but I haven't seen the line up for the year. They are free.
The Village Mall at Adams and Squirrel Roads has concerts - free and usually any music is great for kids. The Auburn Hills Civic Center has concerts off of Adams in the evenings also and they do Lunch concerts in the Riverside Park in downtown Auburn Hills - all free. The zoo does concerts but you have to pay admission obviously unless you have a membership. The Rochester Library has the Candy Band performing outside in the evening this month also. There is music all around and pretty close by. Good Luck