Music = Language?

I just realized that the development of music skills in my life is similar to the development of language skills. I've mastered English, that is to say, I'm fluent and I can express myself with it in an effective and occasionally artistic manner. Likewise, I feel fluent in rock/pop music for the same reasons. But the language of bluegrass mandolin or jazz piano, 2 other areas I would like to develop, are not things that I have mastered. I took 4 years of Spanish in high school; So my working knowledge of Spanish is better than someone with no experience, but not good enough to really express myself in the language, or to converse with a native speaker. I have some vocabulary, some understanding of the grammar, and a idea of the inflections, but I have not developed any of these things to the point of a language that I can really "speak." The parallel to bluegrass and jazz should be pretty obvious then. And by its nature, I think that classical music plays by different rules (that's probably a bullshit excuse). Anyway, I guess I need to practice.