Three heavies ship from Sweden...
Melodically, heavy metal was invented by the Christian church. Honest. At least, the perfect fifths of chanting monks underpin the genre. No, they do. A powerchord is typically a root-note and fifth. Slide it all over a guitar fretboard and you’re riffing. OK, so it’s more complicated than that, but it is reasonable to argue that rhythmically, HM, like much modern music, is rooted in the sounds of nature and aided by technology.
Hitting a hollow log with a stick, mimicking a rapid heartbeat and encouraging people to groove, is technology and nature in cahoots. Kill a mammoth, stretch its skin over the end of a hollow log and you’ve a drum. While it may have taken until the Bronze Age to devise cymbals, rhythm instruments changed little until the early 1930s when Léon Theremin devised perhaps the world’s first rhythm machine, the photo-electro-mechanical Rythmicon. Let’s skip a few decades to land, with a satisfying thud, in the late 1960s and the origins of HM lyricism.
Metal was a reaction against the loved-up, happy-lah-lah of hippiedom; something to remind us that life has a darker side and whatever it was you saw while on LSD might not have been The Truth. Heavy-metal drummers pounded their way through the ‘70s, ‘80s and ‘90s gradually taking up more and more space on stage with twin-kickdrum kits sporting an ever more ludicrous number of toms and cymbals, all while happily oblivious to the technological strides being taken in dance music. A company called Ace Tone, later Roland, had set the ball rolling in ‘67 with the mass-market launch of the Rhythm Ace FR-1. This rhythm machine was a synthesis-based, preset-only affair, hence comparatively limited, but it proved a hit among contemporary musicians and so development continued.