Earlier this month I DJed for an event organized by a Student Group in my university. The event took place on-campus, a few days after the term officially started (i.e. a few days after the first day of class). In order to get paid (a nominal fee to maintain my turntables, cables, etc.) the student group asked me to fill an official Request for Payment, which goes through the finance department of my university, which in turn asked me for my W-9 or Social Security number as the Request for Payment considers me as a vendor / professional service provider.
I am an international graduate student in the same university under F1 visa. Is getting paid given those circumstances allowed by my F1 visa?