“The Rumbling” by SiM is the latest opening/credits song to the shockingly bloody hit anime Attack on Titan, and judging by its Spotify streaming numbers (65 million, and the song’s only been out for 8 months) it’s one of the most-listened-to metal songs of 2022. It’s the most brutal metal song I’ve ever heard used as the theme for a Japanese anime, which makes sense because the show is so unrelentingly violent.

It also has a flattened tonic (Do-flat or De in movable solfege), a note which isn’t supposed to exist.

Why Do-Flat Doesn’t Exist in Traditional Music Theory…

I’ve got to take a step back to explain what I mean by “a note which isn’t supposed to exist.” This note doesn’t exist in a classical music theory system called “solfege.” Solfege is a system where you label each note with a special syllable to track what role it plays in a song’s key or scale. ((This is a system called “movable-do” solfege. There is also a system of “fixed-do” solfege, in which C is always Do, and D is always Re, no matter what key you’re in.)) The home note of a scale, the note that the scale or key is named after, is called “Do.” So if a song is in F major, F is Do; if a song is in G major, G is Do. In a regular major scale, the next note above Do is Re, and the next is Mi, and so on.

C major:	C	D	E	F	G	A	B
	Do	Re	Mi	Fa	Sol	La	Ti

If the pitch of a note changes, its place or function within the scale/key changes, so if a note from the scale is modified with a sharp or flat it is usually given a different solfege syllable. In C minor, the seventh note of the scale is Bb instead of B, and we call Bb “Te” (which means, “Ti-flat”; “Me” is “Mi-flat”). These two notes have different uses and tendencies: Ti (or B in the C major scale) is what we call the “leading tone,” which has a strong tendency to push upwards towards Do, but Te (or Bb in the C minor scale) tends not to lead upwards quite as strongly.

C natural minor:	C	D	Eb	F	G	Ab	Bb
	Do	Re	Me	Fa	Sol	Le	Te

This idea of notes having inherent “functions” or “tendencies” sounds pretty mystical if you take it at face value. But it’s really just a shorthand for human expectations that are built up over a lifetime of exposure to Western music, in which you hear notes being used in the same way over and over. Ti “leads upwards” only because something resembling Pavlovian conditioning has trained us to expect this note to be followed by Do. (Try it yourself: Play a C major scale upwards but stop at B. Your brain will really want you to play C to finish the scale.) ((It’s actually a bit more complicated than Pavlovian conditioning, since a different note is “Ti” in each different key or scale. Sue me.))

Traditional music theory frames the major scale as the default, so the major scale solfege are the default set of syllables, and the others are considered “altered” or “modified” or “chromatic” solfege syllables. In classical music theory, these are only used for “borrowed chords” which come from another scale/key.

Due to the way borrowed chords are defined in classical music theory, “Do-flat” is not considered as a possible option. In classical music theory, the main categories of borrowed chords are secondary dominants, and modal mixture. Modal mixture usually means “chords borrowed from the minor key,” so they use the same solfege as the minor scale. Secondary dominants all have more sharps, instead of flats, with only two exceptions: V7/IV, which is spelled “Do Mi Sol Te” (or C E G Bb in the key of C major) and several viio7 chords. I won’t get into the details of why, but if you follow the classical rules of spelling chords, none of the secondary viio7 chords will ever have a flat tonic; if the same sounding pitch appears it will be spelled as a Ti, not a Do-Flat. Check it out for yourself here.

In fact, the only thing I can think of that could produce a Do-flat in classical theory would be a viio7 chord borrowed from the key of bIII (spelled Re Fa Le Do-flat). If your home key is C minor, viio/bIII would be viio borrowed from the key of Eb major, which would be a D diminished chord. But D diminished is already in the key of C minor; it’s the normal iio chord in that key. So chances are any viio/bIII would be heard as a iio chord, not a viio borrowed from the key of bIII.

So most solfege textbooks don’t bother coming up with an altered solfege syllable for Do-flat. You’ll see this if you look up solfege on Wikipedia, for example; some of their charts don’t list an option for Do-flat. If there were a Do-flat syllable, it could be De (just like Sol-flat is Se). But in classical music theory, this isn’t even an option—it’s impossible. ((In Jazz Theory, there is a common Do-flat in the “tritone substitution” a bII7 chord (Ra Fa Le De in solfege, or Db F Ab Cb in the key of C) that is often substituted in for V7.))

…But Do-Flat Does Exist in the Key of Metal

But Do-Flat or De does exist in metal music. In fact, it occurs naturally in the combination of two of metal’s most popular harmonic idioms: the bII “downwards leading tone” and the bVII “mixolydian dominant.”

bVII (either Te, or a chord built on Te) is super common in metal, and it’s often a legacy of rock’n’roll and the blues. It’s especially closely associated with rock-style lead guitar soloing, and I’ve recently run across a couple of songs where the riffs under the guitar solo have a major Ti but the guitar solo has a Te. ((One metal song which has lots of Ti in the riffs but Te in the guitar solo is “Metal on Metal” by the Canadian 1980s heavy metal band Anvil. Another example, but not metal, is “Personality Crisis” by the New York Dolls.)) The popularity of bVII in metal, and rock more generally, is part of why so many rock songs are described as “Mixolydian mode” (the Mixolydian scale is the same as a major scale with a b7 instead of the major 7).

The bII or “phrygian 2” note (which would be Ra in solfege, or Db in the key of C) can be used in pretty much any metal song, regardless of what key or scale the song is in. It has a super evil sound that is part of what sets metal apart from mainstream popular music (although that’s no longer as true as it used to be, and the history is complicated). It also has this super powerful downwards pull, which contributes to metal’s “heaviness.”

bII can be used anywhere in metal music, sometimes as a “secondary dominant” just like V or viio can be borrowed from another key in classical music theory. So you can have a bII/IV that leads to IV (Gb leading to F in the key of C major).

Or, you could have a bII/bVII that leads to bVII (Cb leading to Bb in the key of C major). That’s exactly how we get a Do-flat in “The Rumbling.” Here’s a transcription of the Chorus:

It’s pretty extreme. I didn’t even realize it was possible until I listened to this song closely. This highlights the fact that classical music theory doesn’t really work for popular music, and especially metal. Metal music needs its own definitions and theory rules, if you want to really understand it on its own terms.

But there it is. Phrygian bII as an applied dominant of Mixolydian bVII. One of the most extreme tonal chords I’ve ever encountered, in one of the most popular metal songs of 2022.

And that brutal bridge breakdown?!? Don’t even get me started. What a world.

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