A Facebook friend of mine, very articulate, a sharp thinker, and with multiple academic degrees in “hard” subjects, was discussing his frustration with only speaking one language, and even so, “don’t ask me about the rules of grammar. On good days, I know what a gerund is.”
Now his written communication is always flawless in spelling and grammar, so he clearly knows how to apply grammar — which illustrates the difference between knowing something and knowing the words for it. Or, if you like, between having internalized a skill and being able to explain it.
Richard Feynman, in “Surely you’re joking, Mr. Feynman!” recalls how his father taught him that knowing the name of, say, a species of bird in several languages still doesn’t teach you anything about the bird. That is true enough, of course, except for one thing — if I know what the bird is called, I can go look it up — trudge to the library for the Britannica or a handbook of ornithology when I was young, or just search in Google or Wikipedia nowadays.
I write a fair amount of highly technical nonfiction in my day job — well enough that I’ve been asked to teach others — and frankly didn’t consciously know any of the grammatical rules until I realized I was able to teach people how something was done, but not why. “This is how it goes, it just sounds wrong otherwise, don’t ask why,” isn’t how thinking people like to be taught. Consequently, I was forced to hit the textbooks myself just so I could “tell people what the bird was called so they could look it up”. I imagine this is a similar situation to people who are self-taught as jazz or rock musician but need to go learn theory just so they can be more effective teachers.
In an interview shortly before he passed away, the legendary jazz trumpeter and bandleader Miles Davis reminisced about a meeting with Jimi Hendrix, planning a recording session that sadly never came to pass due to Jimi’s untimely death. He recalled mentioning a “diminished seventh chord”, and Jimi looking blank. He then took his trumpet and arpeggiated the four notes — Jimi of course immediately played the chord that he’d never known the name of. In fact, Jimi would have stared the same way at the mention of a “major-minor chord”, a.k.a. “dominant seventh-sharp ninth chord” — even though it’s nowadays often referred to as the “Purple Haze chord” or “Hendrix chord” due to its prominent use in one of Jimi’s best-known compositions.
Hendrix “spoke music like a native”, but didn’t consciously know the grammar, if you like — he just could apply it in his sleep. A very different intuitive musician, Evangelos Papathanassiou — world-famous among electronica and soundtrack lovers by the Greek nickname Vangelis — had classical piano lessons but never properly learned to read music: blessed with a prodigal ear and memory, he could reproduce what his teacher showed him just fine. While he apparently took some college classes in music (as did his more meditative German college, Klaus Schulze), he kept an intuitive, “feel” attitude toward music his whole life. When an interviewer in Keyboard magazine asked him how he composed, he answered tellingly: “it’s like breathing: if you think about how to breathe, you choke”.
Now while some of Vangelis’s more ambitious compositions (such as “Heaven and Hell”) clearly draw inspiration from Western classical music (Klaus Schulze even wrote a brief orchestral fugue in the studio version of “Ludwig II”), it would be hard for a musician to “function” in the classical world without the musical equivalent of “knowing your grammar”. (To be sure, at least one famous classical organist needed to learn most of his repertoire by ear — Helmut Walcha had been totally blind since age twelve — but he surely knew his theory, and taught for many years at the Frankfurt Conservatory.) Likewise, in some of the more ambitious, through-composed realms of jazz and progressive rock, a thorough conscious knowledge of music theory is a great asset—though you may be able to get by just fine with an unconscious one, as long as your fellow band members are comfortable learning by ear.
Conversely, knowing the rules without being able to apply them in real time may get you a job as a critic, but won’t get you far as a musician — or a writer.