

You want mpd to server and play the music, connected with a web front end (there are a few to choose from) accessible on the private store wifi. You should probably serve this frontend only to a certain machine on the network (like the managers computer in the back) and lock everything else out. The last time I ripped CDs on Linux I used whipper, which I believe was the successor to morituri. This is all only legal if the CDs they have already included the licensing fees to play them publicly or are themselves freely licensed. There are sources of freely licensed music out there that you can play publicly without paying.






It could have been an accident or incident that resulted in a death. They may have been collecting evidence. There are even some police in my area that uses conventional land surveying equipment and rapid high density laser scanners. Precise measurements of things like skids marks and other evidence of how the vehicles came to rest can be used to estimate initial speeds and confirm or refute the testimony of witnesses.
It could also be something more mundane like an actual land surveyor collecting data to support future design work or verify completed projects.
Neither of these are jobs that can be done at night or at times more convenient for your car.