Conversation so far:
Where did the band form?
Chicago.
Did they play at any Chicago clubs?
Polish bar Chicago 21.
Were they popular in Chicago?
CANNOTANSWER.
What was their big break?
CANNOTANSWER.
Who was in the band during this period?
guitarist James Iha.
Who else?
The duo performed live for the first time on July 9, 1988 at the Polish bar Chicago 21.

Question: Did any other people join the band later on?
Self-contained rewrite: Did any other people join the band later on other than James Iha?