If you don’t know much about yodeling (and I didn’t), you might think of it only as a comical footnote, much as it was in the “Parts Unknown” episode. You might think only of that scene in “The Sound of Music” or of women in dirndls at biergartens wearing fake braids. At least, those were the visions that yodeling called up for me. Faced with the task of writing something about the musical form, I thought, I know nothing about yodeling. I mean, who the hell does? The answer is very simple: author Bart Plantenga, who was kind enough to chat with me from his home in Amsterdam.

Plantenga, I realize, isn’t just an expert on yodeling. He is the expert on yodeling. The story of yodeling is both simple and extremely nuanced. “It’s a long history,” Plantenga says, “but, in a kind of capsule form, it probably arose in numerous places around the world independently. Yodeling most likely originated in Africa, sort of at the dawn of time, and spread from there.” But what about the biergartens and “The Sound of Music”? “It’s pretty characteristic of the Swiss. It’s something that’s always identified with Switzerland, but it’s also in America, India … It’s everywhere, pretty much.”

We’ll talk more about the spread of yodeling later. But right now, since the yodelers Bourdain was trying to avoid are in the Alps, we’re focusing on the Alpine tradition of yodeling. (He’s in good company; as recounted in “A Tramp Abroad,” Mark Twain was initially charmed by yodeling, handing out tips to yodelers, but by the end of his time in the Alps he was trying to pay them to stop.) “It’s a utilitarian call amongst herders in the mountains to each other. Also, the herds were known to listen to particular sounds very well.” (So the lonely goatherd from That Musical does make sense.) The cows and the herders, says Plantenga, “become close. The cows will line up when the herders want to take them up or down the mountain, depending on which of the yodels they use.” Much apart from that, “There’s another kind of yodeling that’s a kind of yodel to mountains, which is kind of a spiritual, naturalist yodel. You yodel into nature and you become kind of one with the surroundings in a sense. Like an om or a mantra—there’s a relationship there that’s specific to the Alps.”

There’s yodeling all through the Alps, but, as Plantenga says, there’s a difference between the yodels of Austria, Switzerland, Germany, and France. Austrian yodeling is “sweeter and more popular-oriented in its tunes and its lyrics,” while the French style is “more pleasant to the ear for Americans; it’s more singsongy, more melodic, less doom [and] gloom.” The German style is “the yodeling that many people are familiar with—that wacky biergarten kind of yodeling for the frivolity and the beer drinking.”

Meanwhile, “in Switzerland, the actual classic sort of yodels, the folk tradition, is much more melancholic, very slow, bluesy—a kind of blues, actually.” Swiss yodeling is a major thing, apparently. “Around 1900 the Swiss government saw that the old style of yodeling was dying out—that kind of melancholic yodel—and the German faster yodel was taking over, so they imposed all of these laws that would try to preserve the Swiss tradition. They have all sorts of rules and regulations, and I liken it to diving in the Olympics. They look for certain kinds of details to make a particular kind of dive a 10, and it’s the same in the officially sanctioned yodeling competitions.” There’s also a political element, Plantenga says. A woman yodeler named Christine Lauterburg made quite a splash in the mid 1980s. “She was very upset that she couldn’t perform at these competitions because at the time there were still no women allowed, and she came to one of these annual performances and she appeared in men’s clothing and caused a huge scandal.” Later Lauterburg would become a huge pop star and appear on a postage stamp as the representative of Swiss yodeling. This, says Plantenga, “upset the traditionalists even more. Because the Swiss Yodeler Federation is also very conservative in the sense of women’s rights, they maintain a kind of macho culture. That’s changed quite a bit; there’s a lot of women involved now. There are all these rules, like about what kind of clothing you have to wear, details that have to be featured, and requirements like those yodeling must put their hands in their pockets while they sing.”

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We move onto yodeling traditions outside Europe. In Africa, says Plantenga, “the Pygmies are the yodelers. It came to America via slavery, and then freed slaves taught cowboys how to yodel. Jimmie Rodgers was probably the most famous yodeler in America. He wrote probably about a hundred songs and about three-quarters of them have yodeling in them. He learned yodeling from African-American railroad workers while he was working as a waterboy.” Rodgers is considered by many to be the father of country music, which explains the presence of yodeling in country music. In India, says Plantenga, there’s a tradition of yodeling in Bollywood. These days a new generation of yodelers across the world is incorporating the musical form into genres as varied as jazz, electronica, and pop. There are even, according to Plantenga, avant-garde yodelers in, you guessed it, Brooklyn.

Though we could obviously talk for hours about this varied, cross-pollinated musical form, you’re getting just an introduction. I’ll leave you with the best thing I learned about yodeling from Plantenga. You know Tarzan’s iconic cry? Plantenga says it’s a yodel, and here’s why: Actor Johnny Weissmuller, the best-known of the Tarzans, was originally Austrian, and he “learned yodeling in Pennsylvania at family gatherings of Austrian immigrants. When he got the role of Tarzan, the character needed to have this wild call, and he said, ‘I know one!’”

Bart Plantenga is the author of Yodel-Ay-Ee-Ooo: The Secret History of Yodeling Around the Worldand other titles. He currently resides in Amsterdam.