I'm a programmer who struggles naming his variables (go figure). Working on a guitar chord api, and already have a designation for the names 'span' and 'interval'. I'm not overly familiar with guitar terminology, and was wondering if there exists a technical term for the distance between any two frets on the fret board. If not, then I'm just going to name is 'sectionInterval' or something else that's made up.
Of course, this is really referring to what your hand does, but I've heard a "3 fret stretch" or "4 fret stretch" plenty of times in casual talk. "It's a big/difficult stretch", etc.
This only works in the context of a single chord or consecutive notes, and maybe that's what you're already using "span" for.
A possible alternative is "reach".
I assume you mean the musical distance, not the linear measurement, since that depends on the scale length of the guitar and becomes less with each higher fret. In musical terms, each successive fret represents a "half step" or a "semitone". The terms are interchangeable.
I know you're already using interval, but I thought I'd mention that interval is a poor choice for a variable name here. Interval has a technical meaning in music, and it requires musical context. For example, notes 3 frets apart could be said to have an interval of a minor third, but it could also be an augmented second. To know which, you'd have to look at the music. So I would advise against anything like this:
Interval = 3;
(Musical interval is actually complex enough to warrant its own class within your software, assuming interval is relevant to your software. Anyone who reads your code and knows about music theory will be left in a state of confused ambiguity upon seeing such an assignment, until they understand the big picture of what your code is doing.)
As far as I'm aware, span doesn't have a technical musical definition, so there no issue using that. You could also call it fretDistance or fretSpan or anything else of that sort. Personally, I would (and have) used halfSteps or semiTones. For example, the distance from fret 3 to fret 6 is 3 semitones.
This is a thing of more relevance to instrument builders than players. Here we’d use terms such as fret spacings or fret distances or even fret-to-fret spacings for the distances between the adjacent frets, or fret positions or fret-to-nut spacings for the distances between the frets and the nut.
So I think in your API fretSpacing could be an option?