Conversation so far:
When did the band form?
September 1984.
What was significant about the formation?
The band was initially named Mogo, and played their first show on University of Massachusetts Amherst campus.
Why did they change the name?
Mascis was so appalled by Nakajima's behavior at the show that he disbanded the group the next day.
What did Nakajima do at the show?
Nakajima used the performance to launch an extended anti-police tirade.
How did the audience react?
CANNOTANSWER.

Question: Did they find a new band member after that?
Self-contained rewrite: Did Dinosaur Jr. find a new band member to replace Nakajima after the original band Mogo was disbanded?