The inspiration for Sarah Alida LeClair’s play “Audition Sides” was the 19th-century romance between pianist/composer Clara Schumann, wife of the famous composer Robert, and another noted maestro, Johannes Brahms. “These two (Clara and Brahms) wrote letters to each other, which are now historical documents, over the course of decades,” said LeClair. “She would never allow them to be together, but they had this love where they were like the other half of each other’s soul. My thought was, who would they be if she were a modern-day opera singer and he was a modern-day actor? How do you behave when you’re in the room with that person?” LeClair’s “Audition Sides,” which her Riot Productions...