Thank you for you this!
For the last couple of years, I play Broadcastify combined with one of those downbeat live channels in YouTube while I code.
This after I tired of http://youarelistening.to/
Waterfox user here. I use different Mozilla profiles for different subject matters (eg, learn.kubernetes, project.xxxxx, stealth, hn.reader, etc). I've had several generations of 'HN reader' browser profiles; each between 3000-5000 tabs. I start a new HN reader profile when the last one's unusable because of the amount of memory required to load it.