I was surprised to see only one other reference to Twitch. I have found Twitch to be AMAZING for new music discovery. MOST of the time when I listen to music, it is actually through Twitch. I have many good hosts saved and checking the who's on now page is the first thing I do when I want to turn on music. And when the apocalypse comes, I have a good library myself now...

There's a catch, of course. A lot of Twitch streamers are fucking irritating! It takes time to find channels that meet my needs...

Plays my kind of music (classic rock, 80s, industrial, darkwave, synthpop, electro, gothic rock, some dance genres like filth... to name a few). If anyone wants channel recommendations I am happy to list some.
Ideally, the video feed clearly shows the track ID (so I know what music to grab!)
The host isn't on mic all the time. It just kills me when I find someone playing good music with track IDs and they talk too much. The more of the video frame taken up by the DJ, and the bigger the mic, the greater the chance that they won't shut up, haha.

A good host will namedrop and raid hosts with similar taste, so once you find a couple that you like, your list of follows will expand quickly.

Here are a few more tips...

If you follow someone on Twitch, there is a separate toggle for receiving notifications when they go live. For 95% of the people I follow, notifications are OFF. A few are so good I want notifications.
"Alternative Player for Twitch" in the Chrome extensions is a cool alternate client that MUTES ADS. There are a few such extensions, this one has been the most reliable for me. However, for some reason it does not support taking you on a raid (that is when your channel ends and sends all the viewers to someone else).
There is a cool alternate client for Android TV called S0undTV.
Some Twitch hosts will put their shows on Mixcloud too, so check their details
Even if a host does not list the track IDs for what they are playing you may have success IDing music with something like Shazaam. On-screen ID is so convenient though.
Get to know a mass tagging tool like mp3tag, and you can RAPIDLY expand the size of your music library.
It seems impossible to tell Twitch to not suggest channels that you are not interested in. You can spend hours trying to kill off bad recommendations but it doesn't matter. For example I do not care about game streaming or people playing live music but I CANNOT get them out of my Recommended list. You just have to learn to ignore them.