A little Hamptons dinner party turned into a summit of the rock gods Saturday night. Jon Bon Jovi and his wife, Dorothea, were celebrating nothing more than the end of summer when they invited some friends over to their East Hampton spread. But then their friends do include Bruce Springsteen, Paul McCartney, Billy Joel, Jimmy Buffett and Pink Floyd’ s Roger Waters.

The surf-and-turf dinner would have been enough for a crowd that included Renee Zellwegger, Naomi Watts, Howard Stern, “Today” anchor Matt Lauer, designer Donna Karan, New Jersey Gov. Jon Corzine, Rolling Stone publisher Jann Wenner and “Saturday Night Live” producer Lorne Michaels.

But, about 11 p.m., Bon Jovi jumped onstage to join the party band. Pretty soon, people were dancing. Before long, McCartney joined Bon Jovi at the mike – along with Joel, Buffett and Waters