It’s fine to say that a musician has found his or her own language, but what does that really mean? First off, what is language, really?
In essence, it’s a symbolic communication method, one that can be transmitted by voice or in written form. So I suppose music, which is similarly conveyed by sounds that make air molecules wiggle, and which can also be represented on a page, can be characterized as a language. But it’s an esoteric one, well suited to certain purposes, but also limited both in what it says and in the many things that it cannot do. You will never use the language that Kyle Bruckmann speaks with his ensemble Wrack to order a pizza, or to explain how that tree in the backyard grew from a seed you could stick between your teeth into something 40 feet tall.