Lou Harrison and Harry Partch are two 20th century composers who composed primarily in just intonation. Just intonation is a microtonal tuning system, i.e. it uses tones in between those of the equal tempered piano. Microtonality is used in non-western music around the world and can also be heard in the United States in Jazz, Blues, and a fretless banjo style called Roundpeak. Lou Harrison was very inspired by Gamelan music and composed for gamelan orchestras. Harry Partch was more inspired by ancient greek music. Partch invented many instruments and recreated ancient instruments, some of which you can see in action here. As far as I know, Lou Harrison is responsible for the invention of the microtonal guitar, which this guy has improved upon by making the frets movable—genius! It’s interesting to note that the reason why the equal tempered piano was developed is because a microtonal instrument can typically only play music in one or two keys. The improved-upon microtonal guitar and some of Harry Partch’s instruments with movable bridges get around this issue, but as you will see in the videos, it is very labor intensive. Happy Weekend, everybody!