When I was in elementary school, I took classes at The Playhouse, the local theater-and-school. That's how I met
mutabbal, my friend of longest standing. Each class culminated in a show we'd developed over the course of the class, performed for family and friends. The year I met
mutabbal, we performed "The Practical Princess".
Presumably it was this fledgling theatrical experience which led me to write a play in fifth grade. It was a musical. It was science fiction. It was called The Rocket Vehicle. My fifth grade glass performed it. My early inclinations - musicals, science fiction - were already going strong, although I have never written another play since.
My entire theater career culminated the following year with my musical theater debut in London, as a singing, plague-carrying sewer rat, part of a student chorus in a semi-professional performance called Flo of the Fleet. It was a history of London, told via the history of the river Fleet, now a sewer, and best known for Fleet Street, which crosses it not far from its outlet into the Thames. My involvement was a by-product of being involved in Drama Club at my secondary school. (Our drama teacher played one of the two lead rats.) And I haven't been in another piece of theater since.
I teach, though, which involves a certain amount of theatricality, performing for an audience, and requiring a clear speaking voice. For the first semester I taught my own full-fledged class, I had butterflies in my stomach every day before lecture. I have yet to figure out how to incorporate musicals sensibly into history of technology, however. (There are non-sensible ways. I bet I could put together a whole course based on "history of tech as portrayed in musicals", but would there really be an audience for it?)