They all work with a number of arts groups and colleges, universities, etc. who present traditional events, and can likely give you some ideas of who might be offering appropriate events you could plug into. The Irish Fest I suggest because Milwaukee is so close to Chicago, and the organizers may be able to give you referrals to "lead-in" type events to the Fest held in Chicago in the month running up to their event, which is HUGE
Do you not have a contact person to work with there?