Upper Structures

[oubiwann]

Most chord modules in VCV Rack support four notes. I use a lot of upper structures when I compose (yes, even when NOT doing jazz 😉) and would like to use them easily in VCV Rack with some of the good chord modules out there.

Layout:

• Key in / Key knob (default C)
• Mode of key (default Ionian)
• Root / tonic for base chord (the 1 output from the chord module)
• 5, 6, 7 out (assumes 1, 2, 3, 4 of "source" chord module)
• Calculate the 9th (out 5), the 11th (out 6), and the 13th (out 7) based upon given key and root
• Switch for enabling "strict" mode; when enabled, the formal rules for "legal" upper structures are followed (so just some of the outs will have values, not all three)
• Possible expanded version?
  • could have an "in" LED showing the implicit chord given the key, mode, and root
  • could have an "out" LED showing the enabled tensions

For the "strict" mode, here is an example of legal tensions for key of C in Ionian mode:

• With root C for Imaj7, legal values: 9, 13 (out 5, 7)
• With root D for ii7, legal values: 9, 11 (out 5, 6)
• With root E for iii7, legal values: 11 (out 6)
• With root F for IVmaj7, legal values: 9, #11, 13 (out 5, 6, 7)
• With root G for V7, legal values: 9, 13 (out 5, 7)
• With root A for vi7, legal values: 9, 11 (out 5, 6)
• With root B for vii-7b5, legal values: 11, b13 (out 6, 7)

(Note that these will change for each mode.)