Rishi is the Knower, Chhandas the Known, and Devata the process of Knowing.
Rishi is the musician, Devata is the spirit or soul behind the music, and Chhandas is the rhythm and structure of the music itself.
The interesting insight here is that rhythm cannot exist independently of structure (the notes and their tone). It is the structure that gives the rhythm something to dance upon. The music, the Known (Chhandas) is the unification of the rhythm with the structure.
Yet, it is the Devata value (the process of Knowing and merging with the music) that gives it a soul, a meaning, a feeling. The musician finds that aliveness, that soul of the music, within, and infuses it into the Chaandas value through the process of Knowing (the Devata).
It is said that computer-generated music is somewhat sterile. Although such music is played with perfection, the process of Knowing is not lively. It is the personified value of the Devata component that breathes life into the music. If that is so, why does computerized Bach inspire so many so deeply?
The Rishi, Devata, and Chaandas value are intimately entwined. For example, we have Mozart, Beethoven, and Bach. A Bach fugue is very mathematical in its nature, lending itself well to computer-generated music. We could say that the Chhandas value, the music itself, has a strong mathematical component. Or we could say that it is the nature of the musician or composer who has an affinity for mathematical structure. Or we could say that it is the Devata value that has the mathematical orientation. In reality, all three components are fully enmeshed, entwined, and inseparable from one another. This is true not only of music, but with everything. It’s what makes the pillow a pillow, a cup a cup, and a tree a tree.