” sludge and stoner metal “
?????
Sludge, or stoner metal would be a slower-tempo, sometimes detuned, but seriously heavy.
Black Sabbath pioneered this genre.
BLACK SABBATH - "N.I.B." (Live in Paris)
In the late 1990s, Queens of tthe Stone Age would carry the mantle of stoner rock.
QOTSA - Mexicola 2001 Big day out (Live)
Today, one of the best bands out there doing this type of music is The Sword out of Austin, TX. These guys are so damn good!
The Sword - Freya (Live At Rockhouse, Salzburg, September 4th 2015)