Blake,
You say you have a production class in the spring. I did the same at Asheville High School, but our production class was students in Theatre III, Theatre IV, and Play Production, all Honors level classes. On alternate years, a Musical Theatre class was offered that same class period, taught by the chorus teacher, which gave us a director (me) and musical director (the chorus teacher.) We never had an afterschool rehearsal until tech week. Students in spring sports were able to participate in the class. As long as someone didn't mess with the master schedule and place us against one-shot AP courses, we filled the class.
If the students in your production class are already earning honors credit, you might want to look at how you are choosing the spring shows. Our Thespian troupe helped me generate a list of potential shows and then narrow them down to two or three. As I always told them, you have to know there are people who will most likely be in the class who are capable of playing the major roles, then forget all of that for auditions. There is no point in committing to a show requiring an actor with great skill at physical comedy if there isn't a likely prospect. Hoping for a great high tenor when there are only baritones in the choir is a very risky way to plan a season. I NEVER precast, but we were pretty certain we would be able to cast a show before we made a final decision to produce it, and the excitement of participating in that decision helped students make the decision to register for the production class.
If you don't already make use of a class library, you might order a bunch of scripts that you would consider for future shows and make them available for students to read.
Good luck!
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CJ Breland
Retired Theatre Arts Educator
NC
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