American Idol finalist Constantine Maroulis is heading to Broadway to join the cast of The Wedding Singer in September (06). Maroulis will play the title character's best friend, Sammy, on the New York City stage until 5 November (06). He is a veteran of musical theatre, having performed in the North American and Asian touring companies of Rent. And Maroulis isn't the only Idol star hitting the stage - third-season runner-up Diana DeGarmo is returning to Hairspray on 8 September (06) in the role of PENNY PINGLETON. She played the role for three months earlier this year (06).