Harry Potter fans everywhere were invited to Douglas Hall Monday night for “Hogsmeade Monday” — a celebration of J.K. Rowling’s acclaimed book series. Visitors were treated to food, games, trivia and a rollicking half-hour of wizard rock, courtesy of Harry & the Potters.

In the Douglas Hall C/D Lower Lounge, there were a variety of activities. Upon entrance, visitors were sorted into the four Hogwarts School Houses — Gryffindor, Ravenclaw, Hufflepuff or Slytherin — based on their answers to three questions.

Once sorted, food was available in the cluster of tables labeled “Diagon Alley.” At Honeydukes Sweet Shoppe, chocolate frogs, canary crèmes, peppermint toads and Hagrid’s deadly rock cakes were available, along with an assortment of other treats lifted from the books. Licorice wands were available from Ollivanders Wand Emporium, and a variety of potions and exotic eggs (bubbles and candy) were for sale at The 3 Broomsticks.

“Right now I’m trying to extort money from people,” said Erin Engle, an NIU graduate and volunteer at several Diagon Alley tables. “So far I’ve managed to get 75 cents for selling some bracelets.”

All donations went to Reading Is Fundamental, the nation’s largest nonprofit pro-literacy organization.

In the main room of the lower lounge, visitors could play Quidditch, or they could find themselves in Azkaban, the Wizard Prison, where they would have to answer Harry Potter trivia questions to be released. “Harry Potter and the Goblet of Fire” was shown in the Smart Classroom, while “Scene-It: Harry Potter Edition” was set up in the Douglas Hall TV room.

“I really liked how ‘Scene-It’ was just a bunch of Harry Potter fans hanging out together and having a good time,” said Chelsea Stephens, a junior at Neuqua Valley High School in Naperville. Stephens was dressed as Hermione Granger for the evening, complete with frizzed hair and a pleated skirt.

The most popular part of the evening came at 7:30, when Harry & the Potters performed in the C/D Cafeteria. The Boston-based duo is made up of brothers Paul and Joe DeGeorge. Paul (a.k.a. “Harry Potter, Year 7”) plays guitar and Joe (“Harry Potter, Year 4”) plays keyboards. The two play to a drum machine and sing songs about anything from rocking to politics to trains — all within the Harry Potter universe.

“Where I come from, the man is the kind of guy who tries to keep you from rocking,” Joe said before their set. “He’s the kind of guy who sneaks into your house at night and kills your parents and puts a scar on your face. So let’s stick it to the man.”

Between dancing, jumping off chairs, jumping off tables, hugging random audience members, running through the crowd with the microphone and convulsing on the ground, the DeGeorge brothers managed to recognize the international theme of Douglas Hall’s C/D Cafeteria and sang the second verse of their song, “Platform 9 3/4” in Dutch.

“The band was very personable” said Susan Urasky, Neuqua Valley High School junior. “They had a lot of great energy. They were definitely the best part of the night.”