Although, one could make the argument that staff notation is itself a form of text, albeit one with a different notation than a single stream of Unicode symbols. Certainly, without musical notation, a lot of music is lost (although, one can argue that musical notation is not able to adequately preserve some aspects of musical performance which is part of why when European composers tried to adopt jazz idioms into their compositions in the early twentieth century working from sheet music, they missed the whole concept of swing which is essential to jazz).

How is that not text? Surely if we consider Arabic to be text (lots of ligatures, grouping, right-to-left notation) then music notes must be, too?