Captain Squeegee. A rare combination of ska and psychedelic rock. Their album To the Bardos! is particularly great, and ranks among my top 5 albums of all time.

The Brotherhood of Dae Han. Southern rock with a hint of black metal metalcore.

Black Bonzo. A modern-ish prog band that sounds straight from the 70s.

Bubblemath. Progressive jazz fusion. Their first album was light on the jazz and pretty low-budget, but their second album, Edit Peptide, is the best in the subgenre, IMO.

Lotus Child. Indie alterna-rock. They only had one album, but it’s creative and interesting.

Tyrant of Death coming in at just over 4000 listeners!

https://open.spotify.com/artist/0v9Vjvjg6Swl0ZzJFEersr

He’s excellent. If you like industrial metal or the Doom soundtrack you’ll probably like ToD. There’s no vocals, so I imagine this will appeal to DnB and EDM fans as well.

I recommend Generation Bliss (link for bandcamp because it’s not on Spotify… wtf bro this your best album!)

https://tyrantofdeath1.bandcamp.com/album/generation-bliss

I must have listened to this 50 times

Monarch ! the slowest band on earth a French Drone metal band who is heavy as hell and plays so slowly that it’s edge between music and noise. Pretty great if you want to set-up a dark-ambience or want to chill out over slow music.

Also they’re great on stage and the musicians are accessible like you can talk with them after the concert

Technically they’re just over the 5000 monthly listeners limit (6955), but Xanthochroid is still relatively unknown and my favorite band of all time, so I can’t not share them.

Future Unlimited. I’m not sure if they still make music, but I love pretty much all their songs. Their most popular upload has just 40k views. They are just criminally underrated in my opinion, I always hoped they’d make it big.

My two favorites of theirs are Destroyer and Golden.