The 19 Tone EDO scale is a means of extending harmony

As A Means of Extending Harmony

Because 19 EDO allows for more blended, consonant harmonies than 12 EDO does, it can be a much better candidate for using alternate forms of harmony such as quartal, secundal, and poly chords. William Lynch suggests the use of seventh chords of various types to be the fundamental sonorities, with a triad deemed as incomplete. Higher extensions involving the 7th harmonic as well as other non-diatonic chord extensions which tend to clash in 12 EDO blend much better in 19 EDO.

In addition, Joseph Yasser talks about the idea of a 12-tone supra-diatonic scale where the 7-tone major scale in 19 EDO becomes akin to the pentatonic of Western music; as it would sound to a future generation, ambiguous and not tonally fortified. As paraphrased, “A system in which the undeniable laws of tonal gravity exist, yet in a much more complex tonal universe. ” Yasser believed that music would eventually move to a 19-tone system with a 12-note supra-diatonic scale that would become the standard. While this has yet to happen, Yasser’s concept of supra-diatonicity is intriguing and worth using to create a sweeter set of harmonies.”