I’ve recently been enjoying some videos from Rob Scallon. Here is his cover a couple of Slayer songs, first on a ukulele, and second on a banjo:
Then, here is his video noting how you can make a pretty decent metal song (at least djent style) using only one note on a 9-string guitar. It is appropriately called 00000:
He’s got some serious songs too, and you can support him here.