“In the world of classical ballet, the presentation of flowers to the lead ballerinas is a carefully choreographed ritual, one steeped in tradition and rules, and perfected by decades of practice. It’s also a study in contrasts, as ushers with no stage experience must walk across the stage to meet the most graceful of performers at center stage. What could go wrong?” You’d be surprised. Peggy McGlone talks with ushers at the Kennedy Center who do it.