So, hear me out...
Drama taught at Hogwarts. Teaching pure bloods, half bloods and muggle borns the art of theatre and instead of having to use massive theatrical lights, having spells for lighting cues, and being able to pull off major stunts. Not needing to spend hefts of money on lighting, hanging mics, microphones, head sets, spacing, and so on - cause you had magic, the great hall (which could be turned into a performance and rehearsal space - or even the room of requirement and having special performances), other departments for physical changes such as Caliban in The Tempest, flowers and plants for set design such as A Midsummer Nights Dream, and soooooo many other things. The only time magic isn't used is when the actors actually act. They're taught the art of theatre, learning lines, being someone else.
Teaching them about Shakespeare, Brekt, Stanislavsky, Arthur Miller, contemporary theatre, theatre for children, further play writes, musical theatre, absolute belters, show tunes, serious topics like Angels In America and the aids epidemic, letting them express their sexuality, themselves, explore other plays and find their forte.
Teachers getting so competitive when their house has a smashing opening night, or just being competitive in general, they want their house to be the best - to have the students be their best. It is a constant battle of showing their capability, a healthy obsession.
Students making their own versions of the founding of Hogwarts and working together to create a masterpiece, future actors, dancers, directors, producers and so many more being given the ability to do some ART, to show their potentional in the magical music/acting/dancing world. Even dancing classes, drama sessions, clubs, how to direct, produce, and so many more skills being taught. It being a mandatory subject up until they can choose to carry it on.
Cause lets be real, theatre at Hogwarts would be so brilliant, and magical. The only magic that isn't used is the students talent.