I first began studying viola with Mr. K after fourth grade, after flaming out spectacularly at piano. Nobody had any reason to have any faith in my musical ability. At ten years old, my track record was awful.

Clearly, Mr. K saw something the rest of us didn’t. With an un-sharpened pencil in one hand, the better to poke and prod, he corrected me over and over again that summer, singling me out from the group. Then when my fingers were burning, he barked: “Again!”

When I look through my earliest music lesson books, they are filled with Mr. K’s handwriting in big red capital letters. Mostly, what he wrote was “AGAIN!” If you were to count up all the words he ever uttered in his entire life, I have no doubt that again would come out at number one.

It quickly became apparent that to Mr. K, there was no such thing as an untalented kid—just a kid who didn’t work hard enough. You are going to fix this problem, he said when he diagnosed whatever was wrong, and there was never any question. Of course you would. It was just a matter of trying and trying and trying some more. He yelled not because we’d never learn, but because he was absolutely certain that we would.

In the eternal debate over nature versus nurture, Mr. K came down unequivocally on the side of nurture. Admittedly, his students, including me, would have been hard-pressed to identify that quality in his particular brand of torture. But with the benefit of hindsight, it’s clear he didn’t care how much innate talent you had. He believed any kid could learn to play an instrument, even someone with a proven track record of failure like me.

“Now you listen to me, seester,” he would bark when he got frustrated. And eventually, no matter how much or how little God-given talent you started out with, you actually did get it right. You knew you did, because Mr. K would give you that highest compliment of all, the one that made you run home and practice even harder: “Not bad.”

There was already too much coddling of kids in school, as far as Mr. K was concerned. The school reform movement that started in the late 1960s had finally, in the 1970s, taken hold in East Brunswick, too. The women’s movement, the civil rights movement, and the era of progressive politics all fed into a new paradigm of teaching that emphasized building up children’s self-esteem and that replaced discipline with praise. The teacher-led model of the classroom morphed into a student-centric model.

In East Brunswick, that translated into “open classrooms” presided over by sideburned teachers who wore Tom Jones—style shirts with tufts of chest hair peeking out and who you just knew spent their weekends at transcendental meditation retreats. The high school abandoned most of its rote learn-the-dates history courses in favor of fact-free seminars like “Racial and Cultural Minorities.” Years later I would say, only half jokingly, that I became a remedial history major in college—I needed to load up on so many courses simply to catch up on the basics that I ended up fulfilling most of the requirements of the major.

Mr. K had nothing but contempt for it all, sticking to his formula of discipline, repetition, and hollering. His insults were cutting; he didn’t care whose feelings he bruised. Once, when one of my classmates proudly displayed a Jackson Pollock—inspired abstract-art project on the rehearsal room floor, he called for the janitor, erupting, “What eez thees mess? Who let the dog een here?”

Yet there was something intoxicating about a teacher who had such absolute confidence—faith, really—in my ability to do better.

Whatever I managed to achieve, he expected more. All I had to do was work harder. It was a simple formula, really, and it seeped into my consciousness without me even realizing it. If I imagined a ceiling on my ability, he raised the roof higher and then shattered it altogether. How far could I go? He gave me no sense of limits, so I set none for myself.

Excerpted from Strings Attached: One Tough Teacher and the Gift of Great Expectations, published by Hyperion, copyright 2013.