Hiya Julie,
Welcome to planDisney! How fun that you are planning a band trip to Walt Disney World Resort in May! You are definitely making me want to dust off my old clarinet so that I can join in.
Walt Disney World Resort does offer group rates, but traditionally they are for conference and convention groups, so I'm not sure if your group would qualify. However, my best advice is to double-check with a Cast Member in Group ticket sales (407-566-5600); they would be able to let you know definitively if your band trip qualifies or not. While I've never traveled with a large group of high schoolers before, I do have one tip to share with you for your trip.
EPCOT's International Flower & Garden Festival is usually in full bloom in May, which is great for groups. The Mouseketeers can split up and grab food at the various booths without coordinating a large sit-down lunch. I recommend having each student get a
Disney Gift Card to purchase snacks, meals, and merchandise during the festival. It is cashless, and once the cards are registered on the website, should they misplace them, they can redeem the card's value later on. This saves the headache that happens if someone were to lose their cash that was supposed to last them the entire trip.
Please come back and see us if there is anything else you need or tips on large group vacations!
Happy Planning,
Ashley F.