Seattle grunge veterans Pearl Jam were confirmed on Monday as a headlining act for the upcoming Made In America Music Festival, set to take place September 1st and 2nd in Philadelphia's Fairmount Park.  Sponsored by Budweiser, the festival is being put together by hip-hop heavyweight Jay-Z, who will headline the second night.  Tickets for the two-day live music event are slated to go on sale Wednesday, and the full lineup of 28 acts will be revealed in the next few days.