I think the kinds of chord progressions you (and I sometimes) tend to prefer are usually ambiguous about whether or not the music’s in a major key or in its relative minor (C vs Amin) and you (and I sometimes) tend to make chord changes that are “weak” by traditional/classical/theoretical/bullshit standards, but of course aren’t weak at all because they sound fine by modern rock-n-roll standards. But I have some things to say about songwriting with guitars and stuff.
BTW, none of this is a criticism of you. I have a lot of the same tendencies. This is just an observation and me thinking out loud and wondering if you might benefit from my thoughts on this. I avoid tritones as well and so does most hard rock music, at least in the guitar and bass.
In music theory, things tend to get broken down into two-chord resolutions, how one chord leads to the next (which can then be seen as the first of the next set of two).
This is typically done via the Dominant chord(V or viiº) resolving to the Tonic (I), and that sequence is often preceded by the Predominant (IV or ii). All of this centers around the Tritone, which essentially only occurs in one place in a Major key, between the 7th and 4th degree of a major key. G7, C… or Bº, C. (Dominant, Tonic), or with the Subdominant F, G7, C or F, Bº, C (F is IV, and is pretty much interchangeable with ii as in Dmin, G7, C or Dmin, Bº, C). The reason the resolve is so strong has mostly to do with the fact that the two notes in the Tritone Interval in the Dominant (B & F) resolve by a half-step (“Leading Tones”) in two different directions! B is a leading tone of C (upward by a half-step) and F is a leading tone of E (going downward by a half-step)
(there are several other layers to this line of thinking, particularly “Tritone Substiution” and Dominants of chords besides the Tonic but the basic deal is that you have a lot of “Leading Tones” which are notes changing by a Half-step to the resolved or next chord, and a lot of chord changes that move up by 4th’s or down by 5ths)
Tritones don’t sound very good to you and me in the lower notes of a guitar when the guitar is the majority of what you’re hearing. You tend to avoid them and so do I. I think the reason why is because they evoke the memory of Blues music when played in bigger chord forms (like an open G7 chord, a regular G with an F as it’s highest note), or they sound kind of like some sort of savage flamenco music when played in smaller chords (like a power chord with a flat 5th)…
The reference to Blues would likely steal the thunder of the kinds of mood you’re trying to keep (especially with your implied preference for modal/classical chord changes). It’s as if the music suddenly yelled “Time to get funky” in the middle of a church hymn, or someone is interrupting “…And many more” as if after singing “Happy Birthday to You” or “…Oh great. A barbershop Quartet!” And when the Tritone is voiced in a diminished power-chord (C, G flat, C) on the lower guitar strings it’s like “Is this a Primus song?”
Diatonic Vs Modal
When I first met you, your high school band’s chord progressions were mostly of a “Modal” nature, and that persists today. I say Modal instead of “Diatonic” because you often don’t emphasize the Tonic. But you do often stay within a key pretty rigidly. This I think is because of guitars and the way rock-n-roll chord voicings are so commonly built. 1, 5, 1, 3, 5, 1 (E type Bar Chord), 1, 3, 5, 1, 3, 1 (G type Bar Chord) and 2nd Inversion Triads (5th at the bottom) 5, 1, 3…
This kind of locked-position playing (using the same basic left-hand shape, as in bar chords) leads to something that traditional music practice has avoided for hundreds of years, the dreaded “Parallel Perfect Interval” But in rock music, it’s almost the *only* thing we do! (power chords).
But your (and occasionally my) preference for Modal chord changes demonstrates a reverence for old time classical uptight properness. And it’s often a beautiful thing.
Counterpoint/Voice-Leading Vs Guitar Rock
There is a very old tradition of voice arranging called “Counterpoint” which is sort of a set of rules for arranging multiple voices. One of the “Rules” of Counterpoint is to never allow Perfect Intervals(PU, P4, P5, P8) of any two voices to move in a parallel motion. If the first harmony was D over G, the next chord cannot be C over F. Instead, you would need to invert one of the harmonies (F over C for instance). Notice, this pretty is much the exact opposite of what guitar’s easy movable chord system encourages.
I think Parallel Fifths/Fourths/Octaves are so horrible sounding in the classical sense that they are the reason that hard rock has such an edgy in-your-face sound. Kind of like a middle finger to the guy with the white wig. Very punk. The Parallel Perfects (Octaves, 5ths and 4ths) dominate EVERYTHING and imply a strong melody, or even more so (or even worse), two melodies that are exactly the same, but a 5th/4th apart.
But with the approach of counterpoint, I think, the goal is more like a braid of tonality. The root of a given chord, or its 5th isn’t the natural note to assume is the melody note. Instead, the highest note you hear is often the melody. Or rather, each part is an independent melody, just as strong as the others, but totally independent. It’s very elegant and beautiful.
We are afraid of the Tritone because of the guitar (but it’s still happening)
So what’s a guy like you or me with a guitar and its typical rock voicings (power chords and bar chords) to do? Avoid the Tritone!
Besides, we all know the Modal chord sequence by heart, at least subliminally, since we’re all trained in it from birth. C, Dmin, Emin, F, G, Amin, Bº, C. For example, when we hear Emin and Amin only, we pretty much already know we’re in C or G Major, or their relative Minor keys, although probably not A Minor because E, the 5 of Amin, would probably be played as E Major in the Key of A Minor. There are only two places in a Major Key where two Minor Chords are a 5th/4th apart. They are iii-vi and vi-ii. So a key is implied with as little as two chords!
A lot of Rock and Folk (and other guitar-heavy) music songs never play the Diminished 5th that makes the V chord or viiº chord “Dominant,” at least not with guitars. But that doesn’t mean it isn’t there. Singers and synths and strings and melodies often play additional notes that turn the overall sound into more colorful chords 7th, Maj7, Min7, Sus, #9 Etc.
Other Instruments Broaden Our Creativity
It becomes really evident to me how restrictive songwriting is on a guitar, when I come up with something on piano, or just singing, or with intuitive synth layering, and then, take it back to the guitar and find myself using all sorts of strange and awkward guitar fingerings that, not only would I probably not have thought of, but if I did think of those chords while working solely on a guitar, I would have thought the chords/changes didn’t “work.”
And I really think this is because of all the “Parallel” 5ths, 4ths and Octaves (Perfect Intervals) that basic movable guitar chord forms yield. For people like you and me, writing songs on a guitar basically guarantees bad form on a certain level: Less good Voice-leading and more avoiding Tritones and Dominants.
It’s all about voice-leading.
In Jazz music, guitar players whom are playing with a group, are pretty much expected NOT to play the 5th of the chord (the root either for that matter). They are supposed to focus on the tonal “skeleton” of the chord, which typically is the 3rd, 7th, 9th, Etc, and perhaps also the melody note, sometimes preferring that note on the top of the chord. Good voicing also means making sure the leading tones (half steps) get utilized!
And in traditional orchestral music, there’s a lot of weight put on the importance of how independent voices move, especially to exploit leading tones.
Modal movements that sound strong on a guitar can be surprisingly not strong when expanded.
Moving from G to Emin, for instance, seems like a big move on a guitar, but in reality, only one note is changing. The D in the G chord turns into an E. Movements of a 2nd, 4th, 5th or 7th make for better multi-melodies than 3rds and 6ths. But the parallel motion of the Perfects (1st and 5th) in a 1-3 or 1-6 chord change hide how little is actually going on. Not that it’s bad to do so, I’m just saying in a way, those weaker changes are variations of the same chord, even though to a lonely guitar, they sound pretty powerful.
I really think it’s valuable to understand the pitfalls of typical/easy guitar chord voicings.
A melody is a much better jumping off point for a composition than a guitar-only sequence made with parallel chord forms, unless they are particularly novel in some way. Or an alien instrument that takes you out of the comfort zone of feeling like power chords are telling you what to do and what can be done.