What kind of chord progressions am I using?

Question

I taught myself music theory mostly by playing with chord progressions and writing music based on what I like. (I've since learned music theory proper.) As a result, I prefer to use some chord progressions that I somewhat rarely see elsewhere over most typical chord progressions.

For example, when a music theory resource introduces chord progressions, the biggest idea that it uses is that chords are usually made up of notes in a scale. So, for instance, the most common chords for C Major are CMaj, dmin, emin, FMaj, GMaj, amin, and bdim.

In contrast, the chords I use the most don't follow that pattern. In major keys, I use almost exclusively IMaj, bIIMaj, bIIIMaj, IVMaj, bVIMaj, and bVIIMaj. I use the same chords for minor key songs, except I switch out IMaj with imin.

Neither of these sets of chords come from their keys, and they don't match any modes, either. My question is, is there any name or common way to describe the chord progressions I prefer to use? Or do I like some pretty unusual chords?

I know that some of these chords appear in common chord progressions. bVI-bVII-I, I-bIII-IV, and I-bII-bVII are three progressions that show up in pop, rock, and EDM and that I use frequently myself.

Answer 1

What you're doing is sometimes called modal interchange, i.e. you 'borrow' chords from other modes with the same tonic. The chords you mentioned when you play in major are taken from the major scale (I and IV), from the parallel minor key (bIII, bVI, bVII), and from the parallel phrygian mode (bII). When you play in minor you just borrow one chord from phrygian (bII). (Note that IV major is perfectly OK in minor, just think melodic minor or dorian). The technique of modal interchange is used a lot in pop/rock and in jazz. Its most frequent use is borrowing chords from the parallel minor key when playing in a major key. Once you start looking for it, you'll find it literally everywhere. There's also a short Wikipedia article about it.

Answer 2

You seem to be using a technique called 'planing' which exploits the fact that any set of chords of the same shape fit well together, particularly when they move by step.