(This is a response by Leigh Cross to a previous post.)
The major problem of we who like to build things is our tendency to see all answers to all questions in terms of a device. I have placed my keyboard in the dumpster.
It is as irrelevant as gourmet rat-poison.
Toward the end of the 14th century, with the advent of keyboards and finger-boards came equal temperament to facilitate easy chromaticism, in those days all the rage. Keyboards and fingerboards may have facilitated chromaticism but it pushed intonation into a restrictive iron cage.
We are now at a point where intonation as an art form is breaking out of that iron cage. There are an infinite number of pitches within the scope of human hearing. The selection of pitch is now a resource of the composer. Ben Johnson does it proportionally; other composers may choose other systems. To try to cage this infinity of resources in a restrictive set, as does a keyboard or fretted fingerboard, is, to put it bluntly, a fools errand.
(Editor’s note: Leigh Cross is a master craftsman who studied music at Juilliard in the 1950s, crossed paths with Harry Partch along the way, worked as a logger, and is an incomparable champion of New Music.)