Children are not necessarily more discerning theatergoers than adults--but they tend to be much more open about their dissatisfaction. Emerald City Theatre Company's musical--based on three stories by Maurice Sendak, including his single most famous tale--held my three-and-a-half-year-old daughter spellbound for its full 70 minutes, though she did fidget whenever things got too scary, moving from her seat to Mommy's lap. Afterward she was full of questions about the props, costumes, puppets, and set pieces used to re-create Sendak's rich, mysterious, monster-filled worlds. But she took for granted the one aspect of the production I found impressive: how well the actors were able to entertain both adults and children without condescending to either. Through 11/7: Sat-Sun 1 PM. Apollo Theater, 2540 N. Lincoln, 773-935-6100. $9-$12. Also Sun 10/31, 10:30 AM, Chicago Historical Society, 1601 N. Clark, 312-494-9509, $25.