Music is often called the universal language. Let us compare how we think about a musician and how we think of a poet. Could you imagine a poet who was illiterate? He certainly might make a few clever rhymes, but his lack of vocabulary would limit most depth of expression. Poor spelling and limited language skills would handicap him even more. Not being able to write things down would even limit his ability to remember and organize his thoughts. Would colored lights, make-up, tattoos, a stage or designer jeans make his poetry better? Formal education is an assumed background for a writer. As a matter of fact, formal education is an assumed background for all skilled people.
A musician with a degree means he can read and write music. He played in marching band, concert band, symphonic band, jazz band accompanied a choir, can follow a director, understand the art of conducting, did musical theater, has knowledge of music theory, studied the history of music and played in a rock-pop group. That is certainly a good starting point. It is not the degree itself that matters, but the all of the knowledge, background, and experiences around it and in it.
To play by ear is an important musical skill. It is a part of music theory. Called ear training it is continuously developed throughout a musicians career. It is not complete without reading and writing music. The music disappears into the air after it is played but to hear it, then write it, it can be studied, analyzed, understood and replayed. Music is a language.