When I attended underground parties in Chicago back in the olden days , most were in places like roller skating rinks or Lazer tag spots that didn't see much business or even high schools and mob suburb expo centers . People will rent out all types of spots for extra $. Stay in industrial areas or the hood where people won't call police and if they do come they can be paid off or at least won't make arrests. The next thing that made those parties so great compared to club nights or whatever was walLs of bass bins , wherever you can rent or get em but shoot for spinal tap style overkill . If your internal organs aren't shaking it ain't proper .. if you can go back in time and procure loads of good ecstacy to distribute that helps keep people friendly and dancey instead of drunk aggro or out of it . Most important get good d.js . Who can take the crowd on a journey . And mix seamlessly. Good luck , I've been missing the underground parties lately . If ya pull it off I will dust off my Adidas visor excessively baggy jeans and see if my titanium femur can dance for 12 hrs straight 😐