Conversation so far:
When did Dinosaur Jr. form?
Mascis and Barlow played together, on drums and guitar respectively, in the hardcore punk band Deep Wound, formed in 1982 while the pair were attending high school in western Massachusetts.
What was significant about Dinosaur Jr.'s formation?
Deep Wound broke up in mid-1984. Cosloy had dropped out of the University of Massachusetts Amherst to focus on running his independent record label, Homestead Records.
Why did the band Mogo change their name?
Charlie Nakajima used a performance to launch an extended anti-police tirade. Mascis was so appalled by Nakajima's behavior at the show that he disbanded the group the next day.

Question: What did Nakajima do at the show?
Self-contained rewrite: What did Charlie Nakajima do at at their first show on University of Massachusetts Amherst campus in the first week of September 1984?