StepMania does not currently run on macOS 10.15 "Catalina".
Install Stepmania. Got a .DLL Error? Watch this youtube video:
Go to Stepmania website.
Click on either Windows or Mac. (NOT CATALINA!)
Install the software (run or save)
Click on the software Icon.
WINDOWS
If you get an error message - check it. If it mentions DLL file. Then follow this youtube link.
https://www.youtube.com/watch?time_continue=1&v=c5fxzdD3tZA&feature=emb_logo
MAC
If you get an error message about note skins follow this thread