I'm not sure if this counts as obscure as its easy to google and someone who knows of ocremix.org might stumble across it, but its a remix of a boss battle song from the end of an almost 25 year old Kirby game, so I think normal people today would never come across it. I've never played the game its from, yet this is still one of my favorite songs of all time
https://youtu.be/eSkrKgqCi1c?si=imEpXyLoSgkxte7V

I play it when I'm really stressed and it helps me calm down (it is not calming music, I don't know how to explain why it helps me)