Its hard to compete with Judy Garland. Which is why you would have thought that anyone staging The Wizard of Oz would take the L. Frank Baum story in an original direction. But Seattle Childrens Theatres production is a carbon copy of the iconic 1939 movieminus Garlands transcendent voice and all the magic that vintage Hollywood had to offer. That said, the current production is entertaining enough. The munchkins are lively. The lion, played by Todd Jefferson Moore, does some slapstick that gets the kids howling. And theres even a little magic in the tornado scene, when storm-struck Dorothy watches images fly across a diaphanous screen and we can almost feel the wind whipping across the theater. NINA SHAPIRO Generally 7 p.m. Fri., 5:30 p.m. Sun.; plus 2 & 5:30 p.m. Sat. starting Dec. 20; plus weekday performances Christmas week. See Web site for exact schedule. Ends Jan. 17.