Complexity of borrowed V in minor mode?

A lot of tabs have no complexity symbol attached to their name. First of all, is this because they contain a chord that’s supermodal in the tab’s relative major?

If so, I’m not sure how Theorytab deals with a V chord in a minor mode, which comes up whenever a song is in harmonic minor. Borrowing the V from major (or Lydian) is shown as a III chord in the relative major, which makes it supermodal. In certain tabs this is no problem, and it gets the usual circles/squares/diamonds, but in others it seems to be the deciding factor in whether the symbols appear or not. In order to get them, the chord has to be replaced with a V/i, so that it will show up as a V/vi in the relative major. I’m sure there’s some other factor I’ve missed, but what is it?

There are four ways in which a Theorytab has no complexity tag:

  • The Theorytab contains any chord supermodal in the relative Major mode except the III chord and its embellishments coming from the 3-sharp supermode, which appears as the Lydian II in Dorian, the Major V in Minor, the Mixolydian I in Phrygian, or the Dorian IV in Locrian. In the Trends database, this 3-sharp III chord and the applied chord V/vi are aliases of the identical chord, whereas III from other supermodes are not considered the same as V/vi, and similarly other borrowed chords are not considered the same as their equivalent applied chords. IV/vii does not equate to any form of III either.
  • The Theorytab contains Beginner II chords, but some of these chords contain an added ninth.
  • The Theorytab was made before complexity tags were supported.
  • Some of the rest chords of the Theorytab are embellished.

The V chord is a borrowed chord in Aeolian mode, but rarely considered as such due to historical treatment of the minor key to simultaneously employ the melodic minor scale in ascending movement and the natural form in descending movement; to some extent this also affects Dorian and Phrygian, which also means chords “applied” to the tonic are incorrect by definition, since nothing from the scale is temporarily tonicized. There are at least four ways to specify chromatic chords, all of which are slightly different to each other:

  • A secondary dominant is the V chord of the major scale transposed to any other scale degree, such that this chord is different from the diatonic chord built upon that scale degree. In general this requires a major third and a minor seventh if present; alteration of the fifth or the ninth, perhaps also omitting the root, leads to various transformed chords including but not limited to augmented triads, augmented sixths, and fully diminished sevenths (by V9no1 in harmonic minor). In contrast, diatonic chords that can be formed by transposing a V chord are called primary dominants, including all such dominant chords on ^5 itself, and certain extensions of I or IV in the relative major key. Neither primary nor secondary dominants are required to have dominant function relative to the next chord degree;

  • Applied chords in contrast are transpositions of the corresponding functional chord of the major key, such that they possess such function relative to the next chord degree. V/ and viio(ø)/ and the most common, though IV/ and iv/ exist, as do ii/ and iiø. Applied chords briefly tonicize the following scale degree that isn’t the tonic, and V/ in particular allows all of the alterations shown above;

  • A borrowed chord is any chord coming from a different diatonic mode of the same key, which does not come from the current mode. These are precisely the chords that do not appear as supermodal in the current key;

  • The notion of major/minor mixture is used in classical contexts. Primary mixture refers to using chords from the parallel major key or any form of the minor key, plus the Neapolitan triad ♭II; secondary mixture refers to altering the quality of the third in a diatonic chord such that it isn’t a primary mixture chord; double mixture refers to altering the quality of the third in a primary mixture chord.

Here are some examples:

Key | Chord  | Dominant  |      Applied       |   Borrowed   |  Mixture
Maj |   I    |  Primary  |         --         |      --      |    --
Min |   I    | Secondary |    V/iv or IV/v    |    Major     |  Primary
--- |  Ib7   | Secondary |       V7/IV        |  Mixolydian  |    --
Maj |   II   | Secondary |    V/V or IV/vi    |    Lydian    | Secondary
Maj |  ii°   |    --     |     vii°/bIII      |    Minor     |  Primary
Maj | bIII7  |    --     |      IV7/bVII      |    Minor     |  Primary
Min | bIIIb7 | Secondary |       V7/bVI       |   Phrygian   |    --
--- |  biii  |    --     |  ii/N or iv/bVII   |   Locrian    |  Double
Maj |  III   | Secondary |   V/vi or IV/vii   |  Supermodal  | Secondary
Min |   IV   | Secondary |       V/bVII       | (Mel. Minor) |  Primary
--- |  V7b9  |  Primary  |         --         |  Har. Minor  |    --
Maj |  bvi   |    --     |  ii/bV or iv/bIII  |  Supermodal  |  Double
Maj |  vi°   |    --     | ii°/V or vii°/bVII | Dorian/Minor |  Primary
Min |  bvii  |    --     |  ii/bVI or iv/IV   |   Phrygian   | Secondary