So, this is gonna sound weird, but I actually find a lot of these bands calming to listen to. I’m autistic, and have a lot of weird sensory issues because of it, so music that’s too simple (a lot of pop or punk or other genres that show up on the radio usually) doesn’t fully grab my attention. Like, there’s not enough happening at once for me to feel immersed in it.
So I’ll end up listening to Power Metal to fall asleep sometimes because I can hear every instrument individually, and my brain switches focus to each one at random times, and it’s stimulating enough that I can be completely distracted from my other senses and calm down. Dragonforce is my go-to because they even have two lead guitarists at the same time.
That said, I do have songs of every genre in my library, and if I do want something slower or simpler, there’s a ton of Metal ballads that aren’t necessarily high energy. Try something like Crimson Day by Avenged Sevenfold, Remembrance Day or Trail of Broken Hearts by Dragonforce, Christmas Truce by Sabaton, or Mother Gaia by Stradivarius.
There’s a lot more examples, but you can certainly have slow, calm metal. I could probably make a decent sized playlist
“Skullehmohgee”