Summerfest is a festival that takes place across 12 stages in Milwaukee over three three-day weekends in June/July. It includes quite a few classic rock acts, i.e., bands and artists who have been drawing big crowds for a few decades, in some cases. There are some lesser known names in the mix, of course, but the headliners are often very familiar names from the past in rock, pop, hip-hop, country, folk, and so on. Note that the festival runs between Thursdays and Saturdays on three consecutive weeks.