Inside Nicole Richie's 30th Birthday Bash
09/26/2011 AT 10:00 AM EDT
Joel Madden led guests in a rousing rendition of "Happy Birthday" while celebrating Nicole Richie's 30th birthday at the Four Seasons Beverly Wilshire in Beverly Hills along with celeb pals such as Mary-Kate and Ashley Olsen and Samantha Ronson. The birthday gal got a Samsung Galaxy S II, which she used to snap pictures all night. After enjoying some cake, the bash turned into an all-out dance party, during which Ronson took the mic and challenged people to a dance-off.