One musician friend said that in heavy metal, it is not only the electric guitar is on a rampage but also the drums. That’s why drummers of heavy metal bands have to take energy drinks because they would be needing lots of energy when they play especially so when the music they play is continuous. Banging the cymbals and the drums is not an easy task when done regularly in succession. But I haven’t noticed that when I am watching a live performance of a a heavy metal band. Maybe it’s my ear again.