What "is" the place of music (classical or other) and the other fine arts in general education and cultural literacy? What should it be? This is a very tough question, and one about which even the most articulate and passionate advocates have serious problems making reasoned and persuasive arguments. It's even a serious question whether music is a fine art at all; Peter Kivy, for one, argues that the label is recent and chiefly a matter of prestige, and the nature of music makes it more a decorative art.
Now of course it's possible to be intellectual "about" music, and one can say that it's possible to be intellectual "in" music (that is, in the music one composes). But can one be intellectual "without" music? I think the burden of proof goes the other way: one needs to show why and how music is "essential intellectual equipment," or at least essential to cultural literacy. And that, I believe, hasn't yet been shown - certainly not in Douglas McLennan's article, and not really in anything else I've read.
Ancient history doesn't signify. "Back as early as Pythagoras, music was considered a key to helping understand the universe. Musical tones helped explain mathematics and scientific principals, and certain combinations of notes were thought to have profound effects on the emotions." But did the ancient Greeks really understand the universe, and can music help "us" do so, or understand mathematics and scientific principles? Surely not. And while music does indeed affect us emotionally, what has this to do with cultural literacy or intellectual life?
One might as readily argue that religious knowledge is essential to cultural literacy. And indeed, though not a religious person myself, I'd say that one can't really understand the history and current state of the world without some knowledge of the great religions. But when fundamentalists of any stripe actually put religious teachings into school curricula, whether in Arabia or Alabama, many of us worry that the development of the intellect, or merely of cultural literacy, is not being furthered but blocked. And we're right.
I care passionately about classical music; I can't imagine life without it, and it's one of the things I live for. But when I look for valid arguments that "everyone" should be musically literate (whatever that is taken to mean), I don't find them. Not even in ArtsJournal.