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Brad Paisley's opener Charlie Worsham says their impromptu concert at a Chicago club is "what music is supposed to be." 

After playing their scheduled concert in south suburban Tinley Park Saturday night, Brad, Charlie, and other openers Randy Houser and Leah Turner went into the city and gave an after-show performance at Joe's Bar that describes as a "jam session/cover song party." 

Charlie tells CMT it was "so exhilarating to be on stage with other artists with absolutely no plan whatsoever."  He adds that the audience was great, explaining that they were "loud and rowdy and didn't care what time it was." 

Paisley and company began their second show at 1:00 a.m. Sunday morning, and played for a little over two hours.  The four of them performed together, taking turns taking the lead on such songs as "Tulsa Time," "You Shook Me All Night Long," and "Sweet Home Chicago." 

Worsham later tweeted:

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