Here we are, the post I threatened to write earlier about how Dark Side of the Moon, as a concept album, uses the signature i-IV dorian chord change as a structural device and a harmonic leitmotiff to explicate the textual motiff of endless cycles, or a highly secularized variation of "vanity of vanities" or "a breath of a breath, everything is a mere breath". If Ecclesiastes were re-worked so that it wasn't Jewish but atheistic British-navel-gazing you'd get Pinkfloyd's magnum opus. And I still happen to like the album. In fact I appreciate it more now than I did in the past, I just happen to like Stevie Wonder in all his cheesiness a little better because he's the greater musical genius. But enough of that digression on Stevie.
The tracks on Dark Side of the Moon are listed as follows and include several chord changes I'll mark off in brackets:
1. Speak to me/Breathe (e minor)
2. On the Run (um, not quite tonal)
3. Time (F sharp minor, coda reprising Breath)
4. Great Gig in the Sky
6. Us & Them
7. Any Colour You Like
8. Brain Damaged
The first actual song opens up with an e minor to A major chord vamp that serrves as the introduction to the whole concept album and lays out the most common harmonic motiff in the songs. "On the Run" is a piece of electronic music that has several chromatic bass lines moving by means of glissandi (for want of a better word) under a rapidly moving static line that oscillates around G with pentatonic notes (g d b d e, as best my ears can hear them). "Time" is written in F sharp minor with a standard i III VII progression at its core. These two songs don't employ the dorian mode and use natural minor or phrygian elements. Of course "Time" recapitulates "Breathe" with new lyrics and returns us to the dorian chord change that began the album.
The closing track on the first side of the record is "Great Gig in the Sky" This song presents us with a simple binary form that is played just twice but to great effect. On the LP this closes off the first half and it opens with an interesting and lengthy chord progression:
(all chords are held for one measure of 4/4 unless otherwise indicated)
B flat major
B flat major
B flat major (half measure)
E flat major 7 (half measure)
B flat major (two measures)
This chord progression takes a full minute before the keys the keys slide up into G minor and the band oscillates between G minor and C major for Clare Torry's solo. This section lasts for about a minute and serves to provide a static harmonic point in the song to contrast with the fairly violent but steady harmonic changes in the opening section. The transition back into the first section comes through half measure shifts from G minor to D flat to G flat to B minor before playing through the entire sequence a second time, this time with greatly reduced textures and dynamics.
I find this interesting as an overall composition because the chain of fourths guides the whole process except at three points where a tritone substition or oblique motion are employed to affect a key change. For the most part the dorian mode is the underlying harmonic vocabulary of this piece even with the key changes. The tritone substitution is the first significant alteration of the harmonic motif, which makes sense since the song is about death, the one part of the cycle of life that we arguably can't completely reconcile ourselves to even if we claim we can.
"Money" is obviously the opener on side B. This is a simple blues number in b minor that is predominantly in 7/4 in the outer sections and 4/4 in the middle. It creates the impression of a ternary form despite being essentially a set of variations on a theme because of the change from assymetric to common meter.
"Us & Them" is in D major, the relative major to the preceding song. At the risk of putting it crudely the song uses a prettified variation of the chords we hear in "Louie Louie". Tonic, submediant superimposed over a droning tonic, passing to a dominant chord, which proceeds to a subdominant chord and on back again. This is a chord progression that in terms of functional harmony sounds cool but doesn't go anywhere, per se. This works well for the song's lyrical conceit that things don't change, that cycles of violence, death, bigotry, and decay continue on and on.
The chorus consists of the chord changes B minor, A major, G major 7th (probably), and C major. Once again a violent sequential change takes place but this time instead of a tritone substitution like we saw opening "Gig" we get a stepwise descent in root movement that sets up a rising root movement of a fourth to the neapolitan chord of B minor, which is used as a subtonic for a harmonically weak transition back in to D major for the second verse. The chords are still moving in predominantly stepwise motion but they've been deprived of the harmonic pedal point that existed throughout the verse and have been subjected to change through oblique motion. If the verses sustain the motif of the set-upon, indifferent "Us" the chorus introduces the motif of "them", who invariably break in upon our indifference and destroy our peaceful indifference, usually through violence or simple death. Fun, huh?
Where "Us & Them" ends is to use the C major chord to create a deceptive ending that leads straight into "Any Colour You Like", which is just a big jam session on i IV but this time in D. "Brain Damaged" retains the tonic-subdominant chord progression but through modal mutation presents them to us through alternating dominant seven chords. D7 G7 D7 E7 G D E7 G D through the verse.
The chorus gives us G A C G, played twice, with a quick transition of B minor, E minor, A to get back into the verse. What's interesting here is that the chromatically altered supertonic lets the band retonicize G as the tonic of the chorus in place of D. That's one of the great things about repeating phrases is that when you employ a harmonic sequence in transposition it does the modulating for you and the listener can expect it.
The final song is basically a classic passacaglia, a compound meter piece with a steadily descending chord progression. D C B flat A throughout to the final cadence in D major.
Now despite the fact that LPs are supposed to be flipped over for a continued listening experience the album wasn't designed with the CD format in mind. But this is an album that, whatever it may lose in getting transferred from vinyl to CD (I don't feel like getting into the debates of audiophiles while I'm writing about this as a song cycle) there is an advantage to cramming the album on to a single disc.
And it is in the CD format that the tryptich pattern becomes apparent. The first song opens with a i-IV progression and "Gig" opens with a tritone substition but eventually gets us back to the i-IV but in a new key. From here follow two more songs before we get another appearance of i-IV, this time in the key of D minor. This is why I've color-coded the three different segments to show how the triptych plays out on CD. The keys in which the signature harmonic gesture occurs are E, G, and D, a sort of extension of the chord progression of "Time" but without any cyclical resolution back to tonic.
But I would never say the members of Pinkfloyd or their production team actually planned the songs as a song cycle in advance, even though a case could be made for that. They planned a concept album dealing with the life cycle but the modulations and harmonic gestures seem more to have come from what comes easily to the fingers rather than through deliberately mapping out every key change and chord change across the entire album. I don't mean this in a bad way but if you're in a rut exploring the same set of ideas then a concept album is a good way to go because your literary and musical gestures will overlap and reinforce each other. This is why I think Dark Side of the Moon actually is a concept album and Seargant Pepper is merely considered to be one, because Pinkfloyd created a musically cohesive whole where the Beatles didn't.
The keys the songs are in are all keys we'd expect a bass and guitar driven band to play in rather than keys that a keyboard player might pick (i.e. there are no songs except "Gig" that employ flat keys. The first side of the album tends to have pieces in E minor or F sharp minor while the second half of the album is predominantly in D. I think the overall effect is that the songs have moved down in overall pitch (a gimme, since that's how it works for the string instruments). It reinforces the downer motif of the album and the persistence of the dorian mode and chains of fourths reinforces the idea of the lyrics that the life cycle is what it is and everything would be perfect if it weren't hopelessly screwed up. It's a kind of art rock exposition on the theme of Ecclesiastes but without any hope, as such.
I still love this album because the musical vocabulary at the formal and harmonic level reinforces that lyrical conceit of the album as a whole. I think this is why the album holds up well and is also why some people don't like it and have gone so far as to say there aren't any really great songs on it. I think that particular view and explanation is patently silly but for people who are looking for individual knock-out songs that you remember apart from any context then, yeah, Dark Side of the Moon doesn't give you that; instead Pinkfloyd gives you a type of rock gestalt. If you listen to it all the way through you can hear that the album is a great deal more than the sum of its pretty good parts. Since no one in the band that I'm aware of is Jewish or Christian my comparison of Dark Side of the Moon to Ecclesiastes is purely speculative on my part. For you it may just be a great rock album or a total bore. I'm just blogging here to lay out the structural and harmonic things about the album that still make the album fun for me to listen to seventeen years after I heard it for the first time.