[gnaritas]

> What stands out here, is that IV → I (F to C) is not only normal, it actually shows up just as often as V → I. This is surprising (at least to a classically trained person).

That's not surprising at all, and I don't believe for a second that a classically trained person would think so either. V -> I is a common movement for resolution, so is IV -> I as are several others. While his data is interesting, I find the analysis weak, he's acting surprised at perfectly known and normal things, even to someone classically trained IMHO. IV -> I isn't "breaking the rules".

[dfan]

Agreed, this is definitely not surprising. In fact, one of the biggest broad distinctions between the harmonic rules of classical music and pop music is that classical music tends to use authentic cadences (V -> I) and pop music tends to use plagal cadences (IV -> I). (If you're curious, in jazz the cadence you see all the time is ii7 -> V7 -> I7.) Of course I am speaking in large generalities; there are millions of exceptions.

The canonical classical music harmonic progression is I -> IV -> V -> I, whereas that famous four-chord sequence that underlies hundreds of pop hits pretty much runs the same sequence in reverse: I -> V (-> vi) -> IV -> I.

[msluyter]

Well, as a classically trained musician, I certainly would expect V-I to be much more common than IV-I, as a cadence. (Defining "classical music" as music roughly from 1650-1900ish). But it sounds like the author didn't really limit his analysis to cadences. My impression was that he just counted every chord that precedes a C chord, which even in classical music would include lots of non-cadential IV chords moving to I chords in the interior of phrases. For non-cadential chord progressions, I'd expect IV-I to be fairly common, though it's unclear to me that it'd be more common than V-I. I mean, just the coda of any Beethoven symphony alone would probably skew the stats in favor of V-I, generally. ;) So, I'd like to see the author clarify that.

As for the explanation, I thought it might have something to do with rock's origins in 12-bar blues (I-VI-I-V-I), though I know that pop has moved away from that considerably.

[baddox]

What you briefly explain what you mean by cadential chord transitions versus non-cadential chord transitions? Is a cadential chord transition one that resolves an entire progression rather than merely appearing in the middle of a progression?

[msluyter]

Yeah, basically. A cadence is a harmonic progression at the end of a phrase. In classical music it's usually V-I. Sometimes you'll hear IV-I (plagal, aka "amen" cadence), but it's actually fairly rare outside of church music. However, internally, within a phrase of music, you might see IV-I more often. A fairly common example: I-IV-I-V-I.

[msluyter]

Ammending: I made a typo -- 12-bar blues should be (I-VI-I-V-IV-I).

[davec]

I disagree that a classically trained musician wouldn't be surprised at the predominance of IV -> I in popular music. Plagal cadences aren't nearly as common as V->I in the common practice period, and when it is used, the pull of IV to I isn't nearly as strong. The resolution is much weaker.

[gnaritas]

Of course it weaker, but tons of two chord songs only have I and IV, it's a sound well burned into our ears. Anyone studying music theory would not be surprised by this. Perhaps I'm meaning something different by classically trained, I just mean trained in theory, not the classical period in history.

I also dislike this idea of breaking the rules, theory is descriptive of music, not prescriptive. There isn't anything you can do that can't be described by theory, that's its purpose. The rules aren't rules, they're just common idioms that people use, using an uncommon idiom is not breaking a rule. Rule is not a proper word to use.

[abruzzi]

It's a slight inversion of expectations. V -> I is more common in classical, but IV -> I is a close second. In this set of songs, IV -> I is more common, but V -> I is a close second.

[jerf]

Your "classical training" is pretty weak if your teachers never saw fit to mention that little tidbit at any point. If mine bent over any further backwards to disclaim the idea that classical chord progressions were the only ones I think their spines would have cracked.

[baddox]

Plagal cadences aren't so common, but this analysis wasn't limited to cadencial transitions.