Well, this is arguably one of the sites I visit most often, as I edit it...
As if Youtube needed an introduction... Anyway, if anything else fails, when I want to check out an artist, I try to find a clip on Youtube.
The first site/app I check, if I want to check out an artist. The sound quality is usually great, and there are no ads.
A fantastic forum for checking out - and buying - new music by independent artists (e.g. Amplifier, British Theatre...)
The Journal of Music and Meaning
I have been the Managing Editor of this academic open access journal for many years now. Check it out if you want to radically step up from the Youtube comment threads.