It's funny you link to Piet; I began Velato by asking what would Piet be as music. Some programs are instantly recognizable as Piet while others are hardly recognizable as such; the language has its own aesthetic and yet programmers bring their own style to its set of visual constraints, all through fairly basic rules. In Velato, all notes are read in relation to a root note that can change between commands, even in the middle of a single chord. That was meant to allow for more choice in how a programmer constructs a piece of music.

Years later I interviewed David Morgan-Mar about Piet and his other languages https://esoteric.codes/blog/david-morgan-mar and wrote about the concept of multicoding, where a single text has readings in two systems that shape each other (an image and code, music and code etc) https://esoteric.codes/blog/chef-multicoding-esolang-aesthet...