Björk did the music theory world a huge favor by writing a pop hit entirely in Locrian mode, since it’s really hard to find a good real-world example of it otherwise.
You don’t see too many melodies written entirely, or even partially, in Locrian mode. It’s not a friendly scale. That mostly has to do with its fifth degree. In a typical Western scale, the fifth note is seven semitones above the root (or five semitones below, same thing.) In the key of C, that note is G. Almost all scales starting on C will have a G in them somewhere. But not Locrian. It has the note on either side of G, but not G itself.
This is confusing to the Western listener. So confusing, in fact, that it’s hard to even hear C Locrian as having a C root at all. Depending on the phrasing, it quickly starts feeling like D-flat major, or A-flat Mixolydian, or B-flat natural minor, all of which are way more stable.
Locrian is traditionally reserved for a specific minor-key use case. Jazz tunes in B-flat minor will sometimes use the chord C half-diminished, the chord you get from taking every alternating note from C Locrian. Like the scale, the half-diminished chord is unstable. It really just functions as harmonic throat-clearing for the following chord, most often F7.
For Björk, the instability of Locrian mode is a feature, not a bug, well in keeping with her general love of exotic scales. She hammers her Locrian bassline and melody into your consciousness through extreme repetition until it begins to make a strange kind of sense.
The “Army Of Me” bassline is only two beats long, so you hear it twice in every measure. Rhythmically, it’s very simple: a stream of six sixteenth notes ending on an eighth note. The pitches are another story. The riff begins by jumping from flat seven to one, back to flat seven, and then all the way up to flat six. In the second beat, it steps down to flat five before plummeting back to flat seven and finally landing on the long root note.
It’s not at all clear which of these pitches is supposed to be “home base.” Since the bassline starts on flat seven, and flat seven is the note that occurs the most frequently, you might well think that it’s actually the root note. The riff ends on the actual root, but it’s in a metrically weak spot, beat three of bar two. The wide interval leaps further challenge your sense of where the harmonic center is. The distorted synth timbre adds to the dark mood.
“Army Of Me” was a legitimate pop hit, climbing up to the top ten in the UK. How is that possible if it’s such a weird and challenging song? For one thing, the track is held together by its strong and predictable beat, built around a sped-up sample of Led Zeppelin’s “When The Levee Breaks.” The vocal melody is as strange and angular as the bassline, but the lyrics are direct and relatable. If you connect with the listener emotionally and make them want to dance, you can get away with a lot of strange musical ideas.
Gosh, Ethan — I’m really enjoying this continued series. The Talking Heads one made me smile, and you put things into words that I was struggling with. I appreciate how you show the notation in both traditional and Ableton forms. Thanks for articulating and explaining so clearly. You make a great point about “If you connect with the listener emotionally and make them want to dance”, or bridging the familiar with the alien, as I like to say. Keep it up, this is educational and fun!
Glad you’re digging these. They’re fun to write. I’m doing them in preparation for an online music theory course, or series of courses, with my NYU research group. We’re building some interactives around it so people can try playing these things. You can read more about it, and try it yourself, here: https://ethanhein.com/wp/pwym-theory/