The actor straps on a six-string for a musical reunion. Plus: Tyra, Lindsay, Britney, Will & Tom and more

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DOING SOME BON-DING

Petra Nemcova teams up with Jon Bon Jovi at the R.S.V.P. To HELP fundraiser in New York City on Thursday. The rocker performed an acoustic set for the event, which raised money for Habitat for Humanity and homeless-aid organization HELP USA.