"Fifth! Fifth!" Daniel Catanach shouts during a brisk tendu exercise in his advanced-intermediate ballet class at Steps on Broadway. "That's 'fifth' with a 'th'!" he adds, making several students' tense faces relax into smiles. Watching Catanach in action, two things are clear: He's all about precision, and he wants dancers to enjoy his class. He's a stickler and a jokester, infusing discipline with humor. "What's the worst that can happen?" he asks during a pirouette combination. "You fall?" one student murmurs. "No!" Catanach laughs. "The worst that can happen is that you do it perfectly! Then you always have to do it like that, because you know you can."