so incase you didn't know already,
summerfest takes place for 2 weeks in Milwaukee from the end of June through first week or so of July
tickets r roughly $20 a day and it's the world's largest music festival (Over 500,000 people a year over the 2 weeks)
these are the first group of performers to headline during the two weeks from summerfest.com:
311, Paulo Nutuni, Trace Adkins, Jack's Mannequin, O.A.R, Miranda Lambert, The Roots, Crystal Method DJ Set, Keller Williams, C C Revisited, Plain White T's, Jacob Dylan, Thievery Corporation and More
There's also the Marcus Amp headlining artists, which for now include Tom Petty, Rush, Stevie Wonder and More...