Sometimes if I'm in a quiet enough place, I hear really soft music in the background or people speaking in the next room, like a radio or something. I was like "oh my god as if I don't already have enough problems" and assumed I was falling into psychosis, but no, it's tinnitus!
Causes and treatments for musical hallucination which is the experience of hearing music when none is being played.
www.tinnitus.org.uk
I obviously have no idea if this is the case for you too and keep an eye on it if you're concerned, but if the noise doesn't progress (i.e.: music gets loud enough that you can't hear real things, music starts telling you to do things) then it's probably nothing to worry about.
It was super alarming to me too
I'm really glad you were able to reach out here about something this scary