Diane Pershing will be joining the cast of Interact's upcoming fundraising performance of Murder, Mayhem and Music, Showstoppers from the Dark Side of Broadway.  It includes numbers from Sweeney Todd, Chicago, Annie, Little Shop of Horrors, Young Frankenstein, Assassins, etc.    The performance takes place on Saturday night, June 28, at the Assistance League Playhouse in Hollywood (1367 North St. Andrews Place Los Angeles, CA 90028).  Tickets are $175 for the preshow dinner and silent auction, as well as the show itself, or $100 for the show alone. MURDER, MAYHEM, & MUSIC SHOWSTOPPERS FROM BROADWAY'S DARK SIDE is a special benefit production, directed by Todd Nielsen . Interact's annual fund-raiser will be a foot-tapping hair-raiser as well, as the company's members and special celebrity guests explore some of Broadway's most beguiling musical numbers, all touching upon humanity's baser instincts. Throughout the decades, the most admired composers and lyricists have frequently applied their talents to presenting the tragic and comic aspects of what drives people to indulge their meanest passions and desires. It all makes for a wild, funny, edgy, surprising, and violently entertaining evening of song.