“Royals”, the lead single from Lorde’s debut album Pure Heroine, ruled the airwaves in the summer of 2013. By some alchemy she parted the indie electro-pop seas with her stacked vocal harmonies and minimalist production and ushered in a wave of a cappella. This was the summer of Pitch Perfect, of Anna Kendrick and “Cups”, and she fit right in with the moment. You could bet that all the collegiate women’s a cappella groups slotted “Royals” into their Fall 2013 repertoire, in much the same way that all the high school marching bands slotted “INDUSTRY BABY” into their Fall 2021 repertoire. It was tailor-made for them.

Me, I didn’t care for it much. I just was aware it was there.

Until some point in the summer of 2019, when I listened to it again and fell in love with one note.

Music theory notation doesn’t sit well with prose, but indulge me for a second.

“Royals” is in D Mixolydian. It spends a lot of time on D major chords. Occasionally it wanders into cadences involving C major and G major, but other than that, it’s fairly static, harmonically speaking. The interest here, besides Lorde’s conspicuous-consumption-satirising lyrics, is mostly timbral, the minimalist production foregrounding her lush vocal harmonies in stacked thirds. I did not expect harmonic spiciness.

So until I revisited “Royals” in the summer of 2019, I had always assumed the harmonic content of its chorus was four bars of D major, two bars of C major, and two bars of G major, rinse and repeat. At least, that’s what the bass notes were telling me.

And then, one morning on the train to Oakland, I heard the F-natural. It made me do a double-take. Did I hear that correctly? And then I heard it again. Instead of going directly from G major to D major, the bass passes by a subtle F-natural on the offbeat.

That’s extremely bluesy. It’s almost a hard-rock idiom, giving me hints of “I Love Rock ‘N Roll” by Joan Jett and the Blackhearts. What’s it doing in a pop song?

And even more spicily: over the F-natural, Lorde hits an F-sharp on the “your” of “Let me be your ruler”. That’s an augmented octave! The most dissonant interval I can conceive on the twelve-tone equal-temperament scale. And yet it works.

Suddenly I’m fascinated by this song. And I’m noticing Lorde doing very bluesy stuff with her melodies. The way the F-sharp of “town” in “in the torn-up town” contrasts with the F-natural of “en-” on “no post code envy”. She knows what she’s doing. And suddenly my musical framework is shattered, and now I’m questioning everything my ears are telling me, the same way I did when I learned about the A-natural in Adele’s “Rolling in the Deep”.