DETROIT—When you’ve seen as many performances as Mary Salmon has, it would be hard to be impressed. The Dayton Ballet choreographer and teacher attended the Jan. 14 performance of Shen Yun Performing Arts at the Detroit Opera House, and she had endless positive comments about the show. “It was absolutely amazing! The choreography, of course! It’s understated when I say it’s extraordinary,” she said. “And I was really interested in the way that the use of props was very consistent. … It was just really over-the-top amazing skill!” Ms. Salmon was with the Dayton Ballet in Ohio, where she was on the artistic staff, choreographed, and taught for many years. Before her tenure with the Dayton Ballet, she was with the Butler and the Indianapolis Ballet. One of the details of the performance that particularly struck her was the use of props in a way that is unique to classical Chinese dance. For …