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.
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.
That was my thought.. I was thinking "I already do this without an extension", so I had to verify that I wasn't using an extension that I forgot about.