Minor chords from MI Rings

25midi · 29 September 2023 14:20

We can produce chords with rings when you set # ringsmodel 1 and change the ringsstruct param. I'm trying to map/document the chord types from the float value of this param, so far I have:

0.025  -> maj
0.3333 -> sus4
0.5    -> fifth (power chord)

Any value > 0.5 just emphazises the fifth, until we get nealry an octave split of the root at 1.0.

Sadly, what It fails to produce are proper minor chords, any value under 0.025 seems to produce dissonant ratios, the only exception is a 7th chord with missing third, which isn't really usable.

Does anyone know how to get minor chords out of rings?
I'm sure that would make me and other ambient heads pretty happy

If you want to experiment with me:

d1 
    $ s "click:2*4"
    # hpf 800 
    # ringsfreq 220 -- A4
    # ringsstruct "<0.00125 0.025 0.3333 0.5>" -- chords i've found, missing Amin
    # ringsbright 0.6
    # ringsdamp 0.6
    # ringspos 0.0
    # ringsmodel 1

25midi · 29 September 2023 14:25

Could it be that the chord tables are defined here? Need to match the ratios with the chords I've found by experimenting..

github.com

v7b1/mi-UGens/blob/9494ef674cb3f9f6d9133fd21e9803c4a40df2d6/eurorack/rings/dsp/string_synth_part.cc#L174


      
              { 4.0f,  7.0f,  12.0f }, // M
            }
          };
          
          #else
          
          // Original chord table:
          // - wider, occupies more room in the spectrum.
          // - minimum number of note changes between adjacent chords.
          // - consistant with the chord table used for the sympathetic strings model.
          const float chords[kMaxStringSynthPolyphony][kNumChords][kMaxChordSize] = {
            {
              { -24.0f, -12.0f, 0.0f, 0.01f, 0.02f, 11.99f, 12.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 3.0f,  7.0f,  10.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 3.0f,  7.0f,  12.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 3.0f,  7.0f,  14.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 3.0f,  7.0f,  17.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 6.99f, 7.0f,  18.99f, 19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 4.0f,  7.0f,  17.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 4.0f,  7.0f,  14.0f,  19.0f, 24.0f },
              { -24.0f, -12.0f, 0.0f, 4.0f,  7.0f,  12.0f,  19.0f, 24.0f },

gamar3is · 14 October 2023 22:54

I was fiddling with this to try and figure it out -- apparently there are 11 chords total (the ringsstruct value is related to kNumChords, according to this file, and here it's set to 11)

I tried using divisions of 11 ((1/11), (2/11), etc) and got fairly ok sounding results, but the manual doesn't help clear up what's happening

Also a note that might help: with ringsstruct set to 0.5 i hear a major third, and with 0.499 it changes to minor