In the 90s I knew a guy in high school who walked around the school in a black trenchcoat with portable speakers tucked inside that were continuously playing Western movie themes. I can only imagine how that bit of creativity would go over these days.
I suppose it was rare enough and somewhat fun in the 90s. Maybe that guy was doing this for others to enjoy as well, or to appear singular (whether it worked or not).
Nowadays it wouldn't appear particularly exotic (portable speakers are ubiquitous) and people playing loud music (from speakers or phones) seem to do this for themselves without caring about the surrounding people, that's just highly egotistical and self-centered. It's usually not music I personally like too.
That's not fun, it's just annoying. There's already too much noise in our cities.
But if you do it right, playing (singular) music for others, reading the room and all, I'm sure it can still work.