PHILADELPHIA – Fifty years to the day after the release of the hip-swiveling tune "The Twist," the man who made it famous celebrated the occasion in his hometown. Chubby Checker performed Friday at a free noontime concert at Philadelphia City Hall. About 1,000 people joined in on the gyrations, some even invited onstage by the South Philadelphia-bred singer. "The Twist," released as a single on July 9, 1960, burst into the rock 'n' roll stratosphere after Checker performed it for Dick Clark on his Philadelphia-based "American Bandstand." Checker's 1960 cover version of the Hank Ballard and the Midnighters song —...