I am curious to know when and how extended chords1 appear in rock music, specifically from the 90s onward. Chord extensions are certainly not unheard-of in rock, but nor are they standard or even common, depending on what sub-genre we’re talking about.2 And that’s the curiosity that I have: when, where, and why do extended harmonies appear? Are there common uses or chords (I△7 for example) and uncommon ones (ii-9)? Do they perform a specific type of affective work when they do appear? In other words, are extended harmonies summoned for particular purposes? And if we tracked these purposes and compared them to one another, would a picture emerge regarding how extended harmonies function in rock music? Of course, when I say “function”, I mean: culturally, affectively, semiotically, emotionally–that is, how they function in our social world, not how they function from the perspective of tonal harmony.What would I find if I followed extended chords around, noting where they appear in the space of this genre? If what we know from popular music studies is that sounds carry both affective (pre-conscious) and semiotic force, this means that certain chord qualities (both functional qualities such as dominant or minor as well as expressive qualities like timbre) accrue social meanings, values, connotations, and functions within the space of a given genre (and its associated meanings, and so on outward). My question is: does the intrusion of an extended chord introduce a new element into a genre space in which such sounds are still the exception rather than the rule? Put another way: we are used to thinking about musical genres as a set of (musical/social/stylistic/philosophical/aesthetic/political) conventions, which are both expressed and partially constituted through sound. From a certain perspective, extended chord qualities can be understood as “unusual” for the genre of rock. And if that’s the case, do they constitute a kind of rupture or momentary irruption when we hear them in the context of rock? For me, the idea of some songs purposefully introducing an external element into their own genre space is a compelling possibility.
1. Because of rock’s firm grounding in the power-chord, I consider “extensions” here to include the 7th.
2. Obviously, the dominant 7th chord is the major exception, given rock’s ties with the blues. But that’s the exception that proves the rule: are we as accustomed to hearing any other extended chord quality in this genre?