Walter Lepore wrote:
> Hi Members,
>
> It's been awhile since I last posted a message. Hope all are well.
>
> I have a question please...
>
> What is in the mind of a "scale builder" when he/she creates a scale?

I can only describe my own perspective, but there are various features
of scales that you can look for: symmetry, variety of interval sizes,
melodic and harmonic resources. One particular kind of scale that
interests me is a scale with two sizes of steps, evenly distributed in
the octave, and subsets of those kinds of scales. The size of the steps
and the ratio of large to small step sizes is another thing to look for.
If tonal harmony is important, the number of good approximations to
small integer ratios of frequency, and where they fall in the scale, can
also be an issue.

> Its been my interest to discover why scales exist, why they are
> created and how to apply these new and old "collection of
> frequencies" to composition. This seemingly "basic" question can
> certainly have complicated answers.
>
> I do have adequate training in music theory and composition but still
> learning the inner workings of tuning theory. Forgive me if this
> question ranks as an entry-level question.
>
> I'd like to know how my question relates to the following:
>
> 1) Designing a scale with Secundal, Tertian, Quartal, and Quintal
> Harmonies in mind.

The boundaries start to blur when you deal with "alternative" tunings.
Take a perfect fourth divided into two equal intervals of 249 cents
each: are those seconds or thirds? But in general if you're looking for
a particular kind of harmony, check the symmetry of the scale. Scales
that are good for quartal harmony will have patterns that repeat at the
interval of a fourth, for instance. With tertian harmony you have to
consider the various kinds of thirds in your scale -- besides major and
minor, you can have intermediate sized neutral thirds, small "subminor"
thirds or larger "supermajor" thirds.

> 2) Designing specific tunings or scales for Composition

A couple of times I've had the experience of having a particular melody
and chord progression in mind, but I had to set it aside until later
when I was playing with a new tuning and realized that it would work
with this old melody. If I were a little more systematic about such
things, I might analyze the harmony and figure out which tunings would
be appropriate. Some harmonic progressions benefit from certain small
intervals (like 81/80 or 36/35) being "tempered out" or at least reduced
in size; in other cases you might want to exaggerate these small intervals.

> 3) Scale builders who create/build scales without composition in mind.

I suppose scales for improvisation would have a different set of
criteria, if that's the sort of thing you're thinking of. (If you're not
planning on making music with it, it's just a list of numbers...)

> 4) Why would a composer choose a specific tuning or scale over
> another.

That's about as easy to answer as why a painter picks a particular shade
of blue. Each scale has its own aesthetic quality; JI scales with exact
integer ratios have a special kind of purity, while Indonesian gamelan
scales have a more energetic quality. Scales with small intervals could
be useful for portraying small things that move slowly. :-) Well, the
reasons don't always have to make sense....

> I'm sure the question will come into better focus as responses begin
> to filter in as it may be covering too broad an area initially.