Over to your right, you'll find a link to something called "The Truck Driver's Gear Change Hall of Shame." The term is someone's colorful way of referring to corny key changes in pop songs: think of every Barry Manilow song ever written (sorry I made you do that), which modulates upward for the last chorus or verse, dragging your sap-ridden heart along its merry melody-line paved with good intentions. Used poorly, such blatant jimmying of the chordal rigging is a cliche, an embarrassment, dirty highlighter all over Trick No. 37 in a beat-up, yellowed copy of the Hack Songwriter's Manual. Used creatively, though - and this generally means, "used to modulate to less obvious keys, or in less obvious places" - such key changes can provide a subtle yet effective insight into the songwriter's craft. When the "Gear Change" site came up on a music mailing list a month or so ago, someone mentioned Tommy Roe's 1969 hit "Dizzy." Without particularly examining the song, the writer claimed it modulated upward with every verse. It doesn't; however, it does something far more clever, moving through a, well, dizzying series of keys that create the effect of constant upward modulation while, in fact, always returning to the same place, in a scheme worthy of M.C. Escher (the painter, not the rapper).
The intro to the song establishes its basic rock'n'roll three-chord pattern, oscillating from D to G to C and back to G again. (Note already the circular motion of chords.) After a brief drum break, what sounds like the chorus kicks in, but this time, after going from D to G, the sequence modulates to B major, which proves to be the dominant of what we think is the new key, E major. We move from E to A to B ("I'm so dizzy my head is spinnin'...") and repeat the same sequence twice. Then, lurchingly, on the line "You're makin' me dizzy," we move to F major, a diminished fifth away from the preceding chord (B), to establish the I-IV-V-IV sequence in F major. For those of you scoring at home, this is the nearly same sequence that opened the track, only in a different key and substituting the V chord (C) for the flatted VII chord in the original sequence. Whew!
We stay here, in F major, for the verse, working that F-Bb-C-Bb series. You will note, we're only forty seconds into the song, we've heard an intro and a chorus, and already we've modulated upwards two times (from D to E, and from E to F). The most important thing, though, is how effortless this all feels: it's an eminently catchy bubblegum pop tune, not some turgid ELP opus.
Okay, so I've already said the song does not, in fact, modulate upwards for every verse, yet it creates that impression. How? After eight bars of the verse, the bridge arrives, and while it remains in the same key, it heightens tension in two ways. First, for most of the song, the chords change every two beats. Now, we change chords half as frequently, giving each chord an entire bar to itself. Second, up to this point, the offbeat's been heavily accented, with both drums and high-pitched string chords. The strings quiet down, and the drums play a steady four-on-the-floor beat for three bars before breaking into eighth notes (double the speed of the four-on-the-floor figure, that is) for the fourth bar. Those first three bars of the bridge stay in the same key, moving from C to Bb to F - but then, at the same time the drums play those eighth notes, we begin to modulate again, moving to A major, which becomes the dominant of...wait for it...D, the key we started in! And voila, we repeat the sequence (with its upward modulations).
The ingenuity here is that this modulation is motivated by the same type of harmonic movement that underlies the initial key change that leads into the chorus. In both cases, we move upward by a major third, and the resulting chord becomes the dominant of the new key. But in the first example, that chord is the sixth degree of its scale, while in this one, it's the third. Because the key change is accomplished through the same device, however, we feel as if we're hearing the same thing. And so, when we modulate upwards into the verse, our impression is that we've been modulating upward all along. In fact, the last modulation moved downward by a minor third (from F to D) but cunningly arranged to do so with upward harmonic motion. Such clever bastards! And because nearly every cell of chord sequences in the song is the simple, basic I-IV-V, nothing sounds complex.
For now, I'll spare you a run-through of Thin White Rope's "On the Floe" - I'll say only that it modulates downward over an entire octave, descending a whole tone each time, through a rather tricky maneuver that initially looks like a half-step upwards modulation.
