Math, science, English, and history classes all have obvious practical value. Everyone will need to do basic budgeting, understand a medical decision, write a resume and a cover letter, or understand how the electoral system at some point, unless they are somehow radically divorced from the ordinary rhythms of American existence. But the value of arts education only becomes clear when schools provide a context for it. Knowing what a half-note is has no value unless you understand its value in a musical piece. Being able to identify a Renaissance painting does you no real tangible good if you only ever see the Venus of Urbino, and her successor, Manet's Olympia, in a textbook. Knowing how to blend watercolors only does you good if someone gives you a palette and paper.
I remember one of my freshman year English professors weeping as he told our class that Milton dictated Paradise Lost while blind. It was an awkward moment, and would have been even more so if I hadn't read Paradise Lost several times before, and been required to memorize sections of it for previous classes, learned those cadences myself. Instead of simple embarrassment at my professor's loss of control, I felt tears pricking my own eyes. The information--and my professor's continuing awe at Milton's skill--were meaningful to me because I understood the text he cared about so much.
Exposure to the arts is not automatic. With the price of museum admissions rising, even though there are many deals available, a trip to an arts exhibition is a pricey choice for families. The same is true of theater and classical music. Arts education isn't something that children have to have to get jobs, or to function on an effective, but basic, level. But we like the idea of giving them the tools to access things that could enrich their lives, that could make them cultured, sophisticated, genteel. But it's silly to ask children to memorize notation, or to drill the name of artists, or to learn about elements of theatrical presentation if we're never going to take them to a concert, or a museum, or a play. If a child has a passion for literature, any teacher with access to a photocopier or a library card can help them pursue it. If a child loves math, they can get far with a good textbook and a relatively inexpensive calculator. It's possible to do relatively sophisticated scientific exploration in a classroom--or outside of it. But the highest expressions of the arts are something that we need to reach beyond the walls of our schools to teach.