Merriam-Webster defines language as "a systematic means of communicating ideas or feelings by the use of conventionalized signs, sounds, gestures or marks having understood meanings." At my high school, students are required to take two years of a language in order to graduate, however many students have a hard time fitting in all the classes that they have to take and all of the classes that they want to take. Although I personally didn't have an issue with this many of my friends were frustrated at the inflexibility that the school allowed.
I had a conversation with a fellow classmate about how band should be a substitute for a language class. The reasoning is simple. Learning music and being able to read it and simultaneously play an instrument contains similar structure and difficulty to that of a traditional language class. To go more in depth into that look at it this way, first you have to learn how to read music. I started playing the flute in 4th grade and although I already knew a fair amount of notes, the class was structured to teach anyone despite their experience. So like a language class they teach you the "alphabet" which in this case are the notes, and then you learn basic "phrases" or chords. Most elementary language classes usually stick to the basic alphabet, phrases and short sentences, however in band we moved a lot faster. Band class in middle schoolwassignificantly easier in terms of content compared to the pieces that we played in high school but considering that many of the students in the class had never played an instrument or knew anything about music, our skill was impressive.
Students who are enrolled in band classes and are committed in my opinion do more work and possess more skill than a student in a regular language class. In language classes you are tested on the material that you learn and more often than not it is usually just a written exam. In band classes you have written exams, and "oral" exams. With that being said your ability has to be on point and you are held to the same expectations as any other class.
So when the school system tries to argue that band cannot substitute a language I leave them with this; true music isn't a "language" but according to the definition that I stated at the beginning students enrolled in band class are communicating ideas through signs, sounds and gestures. Even after they graduate, whether they choose to continue playing their instrument or not, their ability to read music never diminishes. Most language teachers cannot say that about their students.