How would you describe this chord progression?

[Functional]

One of my recent explorations brought up to me something that I'm rather unsure of. So there's two parts to it. First is a repeating Dm | Am | Bb | Bb. Pretty simple stuff, i-v-bVI, right?

But then we get into the territory of weirdness; Dm | C | Em | D which can be followed up nicely with Dm | Am(1st. inv) |Bb | Asus4.

So what would you call it in terms of roman numerals? The reason I'm asking is because I'm simply not sure how to share this kind of modulation idea in terms of roman numerals. i-v-bVI (in aeolian flavor) that modulates a fifth above into minor and turns the progression into iv | bIII | v | IV | iv | I | bII | Isus4

Will I be sent to hell for describing it like that?

I got an audio clip of this too but I think this should be fairly obvious without an audio clip. In every, except one chord, the third (or sus4) is in soprano, from there on this should be very obvious progression.

[Forgotten]

It looks like it’s based on a natural minor scale.

The Em in place of the E dim is odd and the Asus4 is unresolved, but I’m not sure what modulation you’re talking about. There’s a borrowed chord in there, but not sure I see a modulation from Dm to something else.

Not sure what else to do other than use D harmonic minor and alter some of the diatonic chord numbers.

[Functional]

So you keep hearing Dm as the tonic?

[Forgotten]

Kind of. I’m just not sure there’s a reason to modulate from the original key.

[Septimon]

It would be easier to analyze if we had the 7 included.
Tonic First part could be Bb Also Am just as a step towards the Tonic From half step below
(Disclaimer: I’m not a pro)
You might consider C as tonic for the second part as well
ii - I - iii -II (borrowed chord)
ii - vi - bvii - vi(sus)

In a Jazz context you would expect the fifth to be a dominant seventh chord that‘s why Dm as Tonic would be strange.

But I‘m not sure

[Functional]

If it would be on the key of Dm, then you'd have | i | bVII | ii | I | and I don't see there much to argue that it's the tonic unless you extend it to include the previous thing with the passage that ends on Asus4. Likewise, using ears, the ii isn't jarring enough which often is the case if it's an actual ii because that chord typically (from my experience) acts like a pivot chord and if you don't modulate with it, it's going to start sounding easily weird if you tonicize the i degree

https://vocaroo.com/iN8YMPREFmb

In here, I just hear this as somewhat subtle modulation that creeps in what is supposed to be the "ii" (note, there is no Asus4 here, it's an old clip of this)

[Functional]

From jazz perspective, you could be running dorian which wouldn't have the proper leading tone either - not all that uncommon mode to base your harmonic tissue on, right? But I don't think it makes much sense to call it D dorian, doesn't sound like it to me especially because it kind of breaks the main characteristic tone of D-dorian during that Bb

Suppose you could say it's ii - I - iii - II with the second part just having somewhat deceptive cadence as that bVII resolves into vi(sus4) which however can substitute the tonic too so it makes sense, I guess?

[Forgotten]

In a Jazz context you would expect the fifth to be a dominant seventh chord that‘s why Dm as Tonic would be strange.

It’s odd that it’s a v rather than V, as that implies natural minor, and the ii is minor rather than diminished.

Overall I can imagine there being a feeling of lack of resolution with this progression, regardless of which key it is in.

[xtp]

I like that particular change myself - Dm, Am, Bb --- I used to fingerpick that exact progression, but on the first pass [on the Bb] I did a bass run of Bb, C, A, back to Dm --- then repeated the 3 chords, and second time through I omitted the bass run, and instead, played the chords C, F#m, E. [I just got the guitar out and played it through, . . . a bit of memory-lane, I don't really play folk music much anymore, or fingerpick for that matter]

I thought your second part was just moving up a tone and repeating the same interval of i, VII --- Dm, C --- move to key of Em, [i, VII] --- Em, D

[Forgotten]

Suppose you could say it's ii - I - iii - II with the second part just having somewhat deceptive cadence as that bVII resolves into vi(sus4) which however can substitute the tonic too so it makes sense, I guess?

I don’t think it’s going to feel like it resolves if you move from Bb to Asus4. It’s going to feel like it needs to go somewhere else after that to fully resolve.

[Functional]

Suppose you could say it's ii - I - iii - II with the second part just having somewhat deceptive cadence as that bVII resolves into vi(sus4) which however can substitute the tonic too so it makes sense, I guess?

I don’t think it’s going to feel like it resolves if you move from Bb to Asus4. It’s going to feel like it needs to go somewhere else after that to fully resolve.

To me, it actually does feel exactly like a nice, weak resolution. Although one is inclined to think so, harmonic motion doesn't have to be strong (and sometimes it can even be outright fake). If you're talking about the suspended identity, I'm not thinking about that as much as just "vi can substitute I"

[Functional]

I like that particular change myself - Dm, Am, Bb --- I used to fingerpick that exact progression, but on the first pass [on the Bb] I did a bass run of Bb, C, A, back to Dm --- then repeated the 3 chords, and second time through I omitted the bass run, and instead, played the chords C, F#m, E. [I just got the guitar out and played it through, . . . a bit of memory-lane, I don't really play folk music much anymore, or fingerpick for that matter]

I thought your second part was just moving up a tone and repeating the same interval of i, VII --- Dm, C --- move to key of Em, [i, VII] --- Em, D

Mm, I should try this. Wish I had a guitar honestly. Also, that's an interesting way to look at it, i.e. just the same chord change on different degree. There's one progression I toyed around and did exactly that; Am7 | Cmaj7 | Em7 and then Gm7 | Bbmaj7 | Dm7 leading us back to... Am7. I've always thought of it just like that, you do the same exact run a whole step below which happens to lead you back to the original center, it doesn't even sound strongly like modulation, tonicization at best. But the other way to analyze it is that it's just all upwards mediant movement (with a chromatic mediant from v to bvii (assuming Am as the key) until you get to the subdominant and then back.

[Forgotten]

Even without the sus4 you’re ending on a borrowed chord (parallel Major), so that would give the feeling of extending before resolution, and I can imagine the unresolved sus4 adding to that.

Maybe I need to hear it, but it looks like it’s going to feel unresolved.

[xtp]

Wish I had a guitar.

I play guitar but would have preferred to have been a pianist. Most of my experiments are started on guitar, but I put them into cubase to develop further where I have a bass and piano set up --- I draw the notes by hand . . .

[xtp]

I also meant to say --- with your -- Dm, C -> Em, D [if you consider it as moving up a tone and changing key] my tune, with C, F#m, E --- the F#m , E is also [i, VII] so if you played --- Dm, C, [tone] Em , D, [tone] F#m, E --- that would also sound cool.