Alot of the time, you can just email their booking email asking to buy their album with cashapp et al and they'll gladly take your money and ship you a zip file of MP3's, assuming the band/artist is small enough.
yet, you jest.
python -m http.server
In a directory as a lazy way to transfer a file (especially to my phone).It is not encrypted, and I wouldn’t be that surprised if it was also vulnerable in some ways, but it sure is easy (and it is only for lan, and pretty brief).
ruby -run -e httpdYes, it works on Windows, Linux, and OS X.
All the problems with NAT traversal should be avoided in that case.
(Also, being in the same room doesn't always mean direct connection is allowed. I've seen wifi networks that forbid it.)