Whistle Classes in Milwaukee can be found at the 18th Annual Milwaukee Irish Fest Summer School Sunday, August 15 through Friday, August 20, 2004. There are beginner, intermediate and advanced classes. The web link to information the classes on whistles and many, many other Irish things is at http://www.irishfest.com/summerschool/index.htm 
The 18th Annual Milwaukee Irish Fest Summer School is a lead-in to the Milwaukee Irish Fest, August 19th to August 22nd. The Smithsonian magazine call the Milwuakee Irish Fest the Superbowl of Irish Music.