Heard next to each other, Lorde's lead singles from each of her albums couldn't be more opposed in sound. "Royals" had the New Zealand singer/songwriter memorably stalking the plentiful space around kick drums and snaps, while new single "Green Light" embraces the busy pulse of both house pianos and producer Jack Antonoff's signature tumbling percussion. While the latter song's sharp departure from Lorde's hip-hop-indebted style makes sense given the legions of moody clones that have sprouted in her absence, it's surprising nonetheless and (perhaps intentionally) doesn't paint a clear picture of what to expect from her upcoming album Melodrama. The connecting tissue between the two songs–aside from the unmistakable vocals and wry lyrics–is the use of a common but not readily obvious melodic scale. It's called the mixolydian mode and it's the best, most rock and roll songwriting choice one can make.
A brief, nerdy explainer: the mixolydian mode is an old-as-shit scale that's mostly associated with blues-based and alternative rock. You know it from "Sweet Home Alabama," "Sweet Child O' Mine," and Tom Verlaine's mind-bending guitar solo on Television's "Marquee Moon." The chord theory behind why these songs sound exotic is complicated to explain in words (this page does a good visual and audio lesson) but to simplify, let's leave it at the fact that "Sweet Home Alabama'"s chord progression of D - C - G, in the key of D major, is the most mixolydian progression of all (and before any other music theory dweebs come for me in my mentions, I know that you can also interpret that as being in the key of G major). You eventually know them when you hear them, but mixolydian melodies are otherwise ridiculously tough to describe as they don't fit into a major (happy) or minor (sad) feel. This is also what makes them special, especially when someone like Lorde unleashes them in the pop world.
"Royals" follows the exact same mixolydian chords as "Sweet Home Alabama" and the effect it has on this song is immeasurable. Lorde's vocal melody slithers coolly, not cheery nor morose but some odd quality in between. It makes it so that her critique of rap-inspired materialism feels like a confident, sneaky thing. Compare its sly ambiguity to contemporaries like Lily Allen's similarly lampooning "Hard Out Here." Allen's song follows a very typical, anthemic pop chord structure, which dulls the impact of her sarcasm. "Royals" is utterly alien by contrast, even more so after legions of songs that imitated its vibe failed to copy its mixolydian feel, and thus aren't as compelling.
The song also can sound like Lorde is revelling in the very wealth she decries, and that's where the mode and its odd sense of triumph comes in. Nirvana's Kurt Cobain wrote a musical suicide note in "All Apologies," yet his mixolydian melody betrays his feelings and recasts them as a victory of some kind. That closing singalong then becomes even more unsettling, like someone grinning ear-to-ear as they walk off a cliff. In another, less dark example, Billy Corgan's tirade against indie tastemakers on Smashing Pumpkins' "Cherub Rock" is only as venomous as it is because, again, the mixolydian nature makes the song a fuzz-pedal-driven boast. Truthfully, what I've been saying this whole time is that "Royals" has much more in common with grunge than pop and would have been just as great a single in 1993 as it was in 2013.
If "Royals" is a textbook mixolydian composition through and through, "Green Light" is a little trickier to parse. The verse of the song is firmly in A major, then abruptly shifts to a chorus that goes G - D - A. In this key, G major is the essential "flatted seventh" chord of mixolydian mode, meaning we're now in A mixolydian (you could also read this as a total change in key from A major to D major, if you want). That 180 in melodic mode is why "Green Light" feels disjointed, as though someone grafted two unrelated songs together in Pro Tools. But it's the unique feel of mixolydian that makes the chorus sound even more like the cathartic night out that Lorde's heartbroken protagonist is embarking on. She's still upset, but in this moment she is triumphant against her shitty ex.
Words are one thing in songwriting, but they become something more when married to melodies and chords that reveal and underline their base truths. Whether conscious of the mixolydian mode or not (even though her acapella intro to "Team" is as mixolydian as it gets), Lorde gets this on some level, and that's partially why her songs speak louder and cut deeper than most of her peers. May there be many more weird songs to come on Melodrama.
Phil thinks way too hard about this stuff. He's on Twitter.