“These are the things you learn out at the ballpark,” said spoken-word genius Jean Shepherd from his spot in left field, standing before Fenway Park’s legendary Green Monster.

The year was 1969.

And Shepherd, who launched his career in the late 1940s at a string of unpromising and scruffy radio stations, was by then something of a cultural hero.

WGBH commissioned him to record several of his unclassifiable monologues, this one about the intersection — or, we should say, the collision — of Shepherd’s beloved Chicago White Sox with Boston’s Fenway Park.

Shepherd was an urban bard, a late-night raconteur, an idiosyncratic voice as unique as Lenny Bruce or Mort Sahl or Allen Ginsberg.

A touch of the surreal informed and energized his seemingly concrete and grounded insights into the American scene.

“The sound of those balls bouncing off the left field stand … that’s a scary sound. How many times in our own lives do we hear the sound of balls bouncing off that left field corner?” Shepherd asked with the existential zest of one who was — no doubt — indifferent to the answer.

WGBH veteran writer and producer Elizabeth Deane recounted the history of Shepherd’s involvement on the occasion of Fenway’s 100th anniversary:

In the 1960s, New York radio icon and Midwest native Jean Shepherd — the man whose stories inspired the cinematic classic A Christmas Story — made a series of short films around Boston with producer Fred Barzyk.

Barzyk was 22 and working at WGBH, then a little station housed in a former roller skating rink in Cambridge. One Saturday afternoon, idly scanning the radio dial, he came upon Shepherd and fell under his storytelling spell. “He was like this jazz musician using words, taking riffs off his main idea but always returning back again,” Barzyk recalls. “I knew I had to work with him.”

Full of the innocence of youth, Barzyk wrote Shepherd and offered him a half hour of airtime. “All I could pay him was $1 for signing the release,” Barzyk says. Shepherd covered his own airfare and showed up, Barzyk believes, because he wanted to forge his credentials in the academic world and the WGBH stationery used to contact him highlighted the station’s connection to Harvard, MIT, Brandeis and Tufts, among other schools.

The first show, Jean Shepherd, American Humorist, was shot in 1962 on the dock at the Museum of Science with the Charles River as the backdrop. Shepherd told two of his classic stories, including the Ovaltine story, which was later immortalized in A Christmas Story, a holiday favorite based on Shepherd’s semi-autobiographical musings.

When Shepherd finished, the crew applauded. “This wasn’t like our normal shows,” Barzyk says. “We were doing lectures, piano shows and educational courses for distant learners. And here was this guy entertaining us.”

Thus began a collaboration that continued for three decades and included the great WGBH-produced series from the 1970s, Jean Shepherd’s America. The short pieces they produced in the 1960s were called Rear Bumpers after a television show Shepherd had hosted in Cincinnati early in his career.

In October 1969, Shepherd and Barzyk filmed inside an empty Fenway Park. Shepherd’s mood in the piece ranges from dread to admiration. He hurls a ball toward the Green Monster and waits for “one of the most sickening sounds in the entire baseball world,” evoking what it meant to a boy listening on the radio. “This is the fence that has destroyed more dreams … and broken more outfielders’ necks than any other piece of real estate in the history of Western man,” he says.

Footnote: Sheperd’s rapture with Fenway is unmistakable, but he makes a verbal slip and exposes his out-of-town heritage. Can you identify Shepherd’s mistake? Leave your answer — or a comment — below.