Widespread Panic headlined three shows at the classic Chicago Theatre late last week. At the start of the band’s second set Saturday, longtime Panic collaborator Jerry Joseph sat in on vocals and guitar for “Chainsaw City.” Joseph wrote the song for his seminal band Little Women and recorded it for the band’s Pretty Wiped Out. Joseph was in Chicago for appearances with his band the Jackmormons at Chicago’s House of Blues. He will appear at Baltimore, MD’s 8 X 10 this evening, while Panic will appear on The Late Show with Jimmy Fallon tonight.