The greatest single “Hard Nut” dance is the Snowflakes waltz at the end of Act I. No other treatment of this famous music so excites its audience, and again Mr. Morris’s secret is timing. And yet how crazy it is, with these unisex dancing Snowflakes in their bizarre bikini-tutus and skewed shell hats, releasing snow from their hands now in steady drizzles, now like explosions of cocaine. First, we laugh at, then we laugh with, these creatures. They’re preposterous; they’re life-enhancing.