The Merriam-Webster dictionary defines dissonance as being “a mingling of discordant sounds” and “a clashing or unresolved musical interval or chord”. Although which intervals or sounds are discordant has some scientific basis, dissonance is largely a culturally subjective phenomenon. Heavy metal has its origins firmly rooted in Western culture, so it is from this Western standpoint that I will examine the use of dissonance.
The tritone is a musical interval that spans three whole tones and was so synonymous with dissonance in the history of Western music that it has come to be known as ‘Diabolus in Musica’, translated as ‘the Devil in music’. It is quite fitting that when Black Sabbath wrote the title song from their first album ‘Black Sabbath’ about being visited by the devil, they relied heavily on the dissonance of the tritone. (Rohrer 2006) The main riff of the song is a very simple but highly effective G, G an octave higher and then a sustained tritone, C#.
(The main riff from "Black Sabbath". Duhautpas 2007)
The song’s tension filled dissonant riff and demonic lyrics, coupled with the gothic horror presentation of the band had live audiences terrified but screaming for more. The band Black Sabbath, and indeed the song of the same name, are widely regarded as being the founders of heavy metal and the genre’s disposition for gore and the occult. (Walser 1993)
For a genre born of the tritone, it’s no surprise that dissonance has played a major role in many heavy metal compositions since. Thrash metal and Nu-metal giants Slayer and Korn have both relied on the tritone to bring as sense of unresolved tension to compositions, with Slayer even naming the album ‘Diabolus In Musica’ after the interval.
Heavy metal’s propensity for dissonance doesn’t end with the simple tritone, as the flattened supertonic or second is also used extensively to evoke a sense of doom and omen. The flattened second rarely occurs in popular Western music, but is quite common to other musical styles like the Spanish Flamenco, Indian and Eastern European Jewish. Led Zeppelin were masters of contrasting tension and release and would often use these exotic modes to add interest to their compositions. The Led Zeppelin sound was quite influential to heavy metal and the tension created by the flattened second is now a commonplace heavy metal and death metal technique. (Moore 2009)
The shift from the tonic to the flattened supertonic in the bass line or rhythm guitar parts often creates the basis for many metal compositions. The guitar solo is often based in the ‘dark’ sounding Phrygian or Locrian modes, which both feature the semi-tone first interval. These modes may be chosen by many heavy metal guitarists for their natural ease of fingering position, enabling lightning fast solos, but it is likely that the unresolved tension created by the unusual modes and dissonant intervals appeal to the generations of fans.
Heavy Metal bands use the doom and tension evoked by dissonance to connect with an audience which feels that not all is good in the world and seem alienated by utopian views of modern society.
Berger, H.M. 1999, Metal, rock, and jazz : perception and the phenomenology of musical experience, University Press of New England, Hanover, NH.
Duhautpas, F. 2007, Black Sabbath (song), Wikipaedia, 2010 http://en.wikipedia.org/wiki/Black_Sabbath_(song).
Ian Buchanan, M.S. 2004, Deleuze and music, Edinburgh University Press.
Moore, S. 2009, Dissonance and Dissidents: the Flattened Supertonic Within and Without of Heavy Metal music.
Rohrer, F. 2006, The Devil's Music, BBC News Magazine, http://news.bbc.co.uk/2/hi/4952646.stm
Walser, R. 1993, Running with the Devil : power, gender, and madness in heavy metal music, University Press of New England, Hanover, NH.