I’m skeptical of free gigs but my advice is if a venue asks if you to do a free gig ask them if there is a opening in their DJ rotation & if this is your audition for that spot. If they say “there are no openings” or “not right now” ….red flag you’re being used for a night of free entertainment. Now you still may consider the gig b/c you want it on your resume however don’t be surprised when you don’t get a call back either.
A little while back a lounge type venue asked me to come out & audition …30 mins @ 10pm, obviously while they have patrons. I go hook up do my 30 mins and the manager comes up and says great job & would I mind just playing out the rest of the night til 1am …HOWEVER it’s still considered my audition and auditions are unpaid. Cut to the chase they didn’t have a DJ that night.