There are only 12 notes in contemporary music. Unless you’re into Middle Eastern, Asian or some other niche cultural music, almost the entirety of music you’ve heard was made with 12 notes (there are small exceptions when you bend notes, but bent notes are rarely used for the entirety of a song, so it doesn’t count). For non-musicians, this is pretty mind-blowing, because that seems like such a small number for all the songs we listen to. This is because all western music is based on classical musical theory that was established around the 18th century. Even metal abides by this, because most instruments are constructed in a way that only allows for the notes defined by this theory. But the truly dedicated avant-garde artists have obtained or even self-constructed specialized instruments that allow them to play music outside of these boundaries.
The word “microtonal” comes from the fact that you have access to tones that are smaller in interval than allowed by the 12-tone dogma. Common examples of this are either fretless guitars (no tone structure at all, every sound is possible) or 16-tone guitars (dividing the same range of sound into 16 tones instead of 12). Today we’re going to be taking a look at these. Beware: Since most people are inundated with music based on these 12 notes that we all know and love, it is likely that these songs might sound like absolute nonsense/noise, but remember that it’s just a matter of perspective. Different countries in the world can be more attuned to these sounds, and the point is that we need to appreciate the out-of-the-box thinking of bands that do this. Unfortunately there are very, very few metal bands who do this, because of lack of instruments, the extremely out-there sound and the increased difficulty in writing songs.
Probably the most popular band who write microtonal metal are M.A.N. Their ex-guitarist Rob Guz had self-constructed guitars with varying divisions of a scale. Here’s one of M.A.N.’s most well known songs, Logocide:
Here’s a less known band that also uses a microtonal guitar (16 divisions to be precise) to great effect. They’re called Asteroidi Esadecafonici. AE are a psychedelic avant-garde metal band. The “detuned” sound of microtonality gives them the sense of disorientation that is sought by psychedelic music.