Young Hollywood goes behind the scenes at the Ahmanson Theatre in L.A. to get the backstage scoop on the hit Broadway musical 'Mary Poppins' from the Practically Perfect nanny herself, actress Rachel Wallace! After checking out the call board and Rachel's costume rack, we head to a rehearsal space where she and two other actors teach us how to physically spell out the title of the show-stopping number, "Supercalifragilisticexpialidocious"! Hosted by Lesley Robins.. Check out more episodes of QUIET ON THE SET by clicking HERE