Where is the viio7 chord?

I was not able to figure out how to create a viio7 chord. Missing feature?

@Hooktheory has never added the viio7 chord into Hookpad.

Doesn’t that seem like…i dont know…kind of a… major OVERSIGHT?

Unlike other software, Hookpad does not allow users to insert arbitrary chords into progressions, instead it limits selection to chords available in major scale harmony. In this way Hookpad serves an educational as well as practical purpose.

However, HookPad isn’t limited to one major scale key, it adds another dimension by allowing the chords to be borrowed from the major scale in other keys.

Some of these borrowed chords are applied or functional, for example, the II maj is acting as secondary dominant, V of V:

I Maj -> vi min -> II maj -> V maj -> I Maj

But you can also borrow chords from other keys in arbitrary ways, non-functional chords, that may nevertheless work in the context of the song:

I Maj -> II maj ? IV maj -> I Maj

The above is covered here:

Using borrowed chords you can write many unconventional progressions, but due to the intervals in the major scale, there are certain chords that you won’t encounter, these include (among others): diminished 7th, augmented traids and maj/min 7ths.

To provide these chords, to my understanding, HookPad would either need to add them as arbitrary additions, or integrate alternative harmonies that do provide such chords, such the harmonic or/and melodic minor.

Besides the technical complexity involved in implementing this change, major scale harmony is reasonably straightforward, borrowed chords, less so (and though I personally find it elegant) adding a third dimension, ‘borrowing chords from alternative scales’ would likely lead to a lot of confusion, especially since I’ve never seen harmony taught in this manner.

Any additional thoughts on the topic would be appreciated. Thanks.

The melodic minor scale does not provide a fully diminished seventh chord.

I don’t know if you were behind the creation of Hooktheory, but to be really educational about fully diminished seventh chords, they arise from V♭9no1 instead of a “harmonic minor scale” – in common practice there is simply a single Minor key that uses ♮6 or ♮7 while ascending, but ♭6 or ♭7 while descending, which may both appear simultaneously (to some extent common practice harmony does not have a separate Dorian key/mode).

For anything the Hooktheory staff decides to incorporate into Hookpad, they must also prepare the relevant content in the Hooktheory book, and I believe it is much more instructive to introduce the viio7 as in classical harmony, rather than introduce new scales when the fully diminished seventh chord is encountered. But, Hookpad must also make it possible to use the dim7 chord on all 12 pitches rather than only 7 as, for example, the altered applied viiø7/.

@HertzDevil, I’m not behind the creation Hooktheory in any way, just a contributor to the forums that saw this question lingering and decided to answer based on my understanding.

To clarify for others, the melodic minor does not provide a fully diminished chord, it is available in the 7th mode of the harmonic minor. The melodic minor does contain augmented triads and the maj/min chord which are also unavailable in Hookpad.

Regarding extended borrowing, I’m not sure why you think it would limit users to 7 pitches. Correct me if I’m wrong, but using supermodes, the non-diatonic borrow function in Hookpad provides access to 84 distinct chords. (7 chords x 12 keys).

If implemented the way I envision, the user could select ‘Harmonic Minor’ and have access to 84 additional chords, including the 12 missing diminished 7ths. But why stop there, ‘Melodic Minor’, ‘Harmonic Major’. Hookpad doesn’t support 9,11,13 extensions, but if it did, these would all be distinct chords.

Personally, I would prefer to see Hookpad be as chord complete as possible (including upper extensions). Admitedly the above is a mathmatical approach, so likely not to everyone’s taste.

Ultimately, I believe we’re rehashing this discussion:

@HertzDevil has outlined two approaches for implementing augmented chords:

  1. The addition of a harmonic minor scale and its modes.
  2. An “aug” embellishment

and I’m advocating approach #1.

If you could eloborate on the more educational approach to fully diminished seventh chords, I’d be interested. Thanks.