YSK: You can install an extension on Firefox (android) that allows you to play YouTube videos with your screen locked: (perfect for listening to obscure music)

It can be a bit buggy at times, but when it comes to just playing music with the screen locked, it's perfect.

https://addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/

Edit: I forgot to also mention that ad blocker extensions make sailing the seas on mobile much more manageable. Extentions, in general, have been a really nice addition.