Well, you have 3 different groups there.
Only Ice-T could be in the rap category.
Mother Love Bone is considered "grunge" by some and
Pantera is hard and loud...metal, even.
Here we come, reach for your gun
And you better listen my friend, you see
It's been slow down below,
Aimed at you, we're the cowboys from hell
Deed is done again, we've won
Ain't talking no tall tales friend
'Cause high noon, your doom
Comin' for you, we're the cowboys from hell