Aristoxenus (Pythagorean student of Aristotle) seemed to have developed a proto-equal temperament system. Written about by this guy (not peer reviewed, but has

Aristoxenus (Pythagorean student of Aristotle) seemed to have developed a proto-equal temperament system. Written about by this guy (not peer reviewed, but has good presentation of the original Aristoxenus) https://siementerpstra.com/aristoxenus/ https://siementerpstra.com/aristoxenus/ http://terpstrakeyboard.com/about/ http://terpstrakeyboard.com/about/