What open-air stadium in Philadelphia hosted the 1985 event that was billed as the "global jukebox"? 
Live Aid:  Billed as the "global jukebox", the event was held simultaneously at Wembley Stadium in London, England, United Kingdom (attended by 72,000 people) and John F. Kennedy Stadium in Philadelphia, Pennsylvania, United States (attended by about 100,000 people). John F. Kennedy Stadium (Philadelphia): John F. Kennedy Stadium (formerly Philadelphia Municipal Stadium and Sesquicentennial Stadium) was an open-air stadium in Philadelphia that stood from 1926 to 1992.
John F. Kennedy Stadium