A co-ed international professional music fraternity and honor society that doesn't act like it, usually causing other problems to the other music frats like unnecessary drama, baggage, and cock blocking. If no other music frat is around them, they will turn onto each other to cause drama just so they can have something to talk about.
MPE Girl 1: "Hey, did you hear what those Delta Omicron people did in the music hall last night?"
MPE Girl 2: "Delta Omicron isn't at this school."
MPE Girl 1: "I heard your boyfriend slept with our president!"
KKPsi Guy: "There goes Mu Phi Epsilon!"