I have programmed an interface for composing in extended Just Intonation tunings. I used the Pure Data programming environment, which is just for this kind of thing.

The idea is that harmony comes from the ratios between the frequencies of notes. Our teachers teach us to add musical intervals, but to understand what is actually happening you must multiply frequencies. Pythagoras knew this, as did some little-known Chinese theorists before him. The Renaissance saw many passionate arguments over how musical notes should be tuned. Pure harmony lost, and convenience won, when the 12-note octave and keyboard became standard.

I learned this particular tuning theory from the writings of Harry Partch; what I offer is an extension of his famous 11-limit 43-tone scale; my default setup is 13-limit, and not restricted to any number of tones- an infinite scale. Partch would have loved this, although he may have been disappointed that the interface is somewhat untheatrical. He dreamt of unlimited JI tuning capabilities, which is what this program offers. Me, I dream of funding to develop this in a compiled programming language, so less computer-oriented musicians can learn to use it without having to set up Pure Data. I also dream of creating a live-performance version, but hardware is a problem.

The Program:
Windows Installer
Mac Version (see README file)
The Pure Data patch.

This program runs in the Pure Data programming environment, using the cyclone, toxy, and zexy external libraries, all of which are free, open-source software, as is my program. Feel free to email me with questions on either my sequencer or Pure Data setup!