Nicknames tell stories. Typically, the focus is on who coined the tag, and why. But we learn even more about a person from the labels they choose for themselves.

While Edward Kennedy “Duke” Ellington attributed his nickname to a boyhood pal, young Ellington didn’t need to be reminded of his majesty. See his youthful edict to his family that he was “ze grand, ze great, and ze glorious Duke Ellington.” His sister and parents were allowed to use “Edward,” the formal version of his given name, but not “Eddie.” Bandmates could address him as “the Governor,” “Guv’nor,” or “Guvvy.”

Same with jazz pianist and composer Williams James “Count” Basie. He wasn’t born to the manor but wished he had been. He crowned himself “Count” not long after putting down roots in Kansas City, in the early 1930s. As his career took off, he chose even more imperial nicknames, such as “Chief,” “Holy Man,” and “the Jump King of Swing.”

Louis Armstrong’s moniker has a more convoluted, and less pretentious, origin. His early one was “Little Louis,” first a reference to his age, then, over time, a joke about his growing girth. Other youthful epithets included “Shadmouth,” “Dipper,” “Dippermouth,” “Gate Mouth,” and “Satchel Mouth,” commentaries on his enormous mouth. Or were they? “Satchel Mouth” was rumored to go back to his days dancing for pennies in the Battlefield, an area in New Orleans. Scooping up coins, he stuck them into his mouth for safekeeping.

Later, he picked up other nicknames, including the less-than-flattering “Boat Nose,” “Hammock Face,” “Slow Foot,” “Rhythm Jaws,” “Sackaface,” “Henpeck,” “Brass (or Iron) Lips,” “Laughin’ Louie,” “Fats Armstrong,” and “Ambassador Satch,” which journalists liked. His mother called him “Louis,” never “Louie,” but two of his wives, his manager, and bandmates liked the less formal Louie.

His best-known nickname is “Satchmo.” In Armstrong’s retelling, it was Percy Brooks, the tongue-tied editor of a British music magazine, who created the nickname in 1932. “I got off the boat and he shook my hand and said to me, ‘Hello Satchmo.’ I had never heard the name before,” Armstrong told biographers. “I love it.” He embossed it on his canary-yellow stationery, named his specially blended cologne after it, and told journalists it was part of his official name and didn’t require quotes around it.

“Call me anything at all,” he told an esteemed jazz writer. “Just don’t call me too late to eat!”

Billy Basie crowned himself “Count” not long after putting down roots in Kansas City.

It wasn’t just nicknames that banded jazzmen together in that age of blues and bebop. They had a lexicon of their own that encompassed takes on songs, life, and fellow artists. The musicians never used this lingo with the public. If fans overheard them, they would not have understood—and that was the point. The secret language allowed performers to talk privately, the way immigrant parents spoke Yiddish or Polish to keep things from their English-speaking children.

“There are more than four hundred words used among swing musicians that no one else would understand,” Armstrong wrote in his 1936 autobiography.

The jargon meshed naturally with the music they played, since jazz itself was an underground language. Jazz musicians took some expressions from Black communities and small towns in the South. “Ofay” was a not-so-fond way Blacks referred to whites. Blacks in the North referred to the South they’d left behind as “Galilee.” A “handkerchief head” was a close relation to an Uncle Tom. Musicians preferred “Negro” to “colored,” and, later, to “Black.”

They had special terms for music, especially for jazz, which became a verb as well as a noun and adjective. A “cutting contest” described a battle of pianists or bands to see who shone brighter or riffed longer. Up-and-coming players disparaged the old guard as “moldy figs.” “Taking a Boston” was another way of saying “getting off” or, more simply, “swinging.” The musicians turned “funk” on its head, changing its definition from “dejected” to “in the groove.”

The vocabulary used for sex and women in those male-dominated bands skewed loutish. “Chili bandits” were the girls who chased musicians, while “sporting women” were whores. When a good-looking lady passed by, bandsmen would say, “Want some, want some,” and for less attractive women, they’d mutter, “Want none, want none.” “Barbecue,” “canary,” and “pigeon” were slang for a woman; “vonce,” for sex. A super-abundance of good things left you with the “Too-Sies”—too much money, too much drinking, and too many women at too young an age.

Nobody played more word games than Armstrong. He used expressions like “yassuh,” “no suh,” “boss,” and “cullid” to outfox the police and bigots. A “butter-and-egg man” was a small-time big shot, a “paperman” played written rather than “head” music, and an “alligator” was a listener, sometimes a white jazzman trying to learn—or steal—from Black ones. “Mugging light” was soft swing, “mugging heavy” was the opposite, and “gutbucket” was swinging to the blues. Satchmo expressed regret by vowing to never repeat something “as long as I’m colored.” He promised never to be “dicty,” which referred to snobbery at its worst.

Ellington’s glossary was long, too. “Juice” and “charge water” were other ways of saying liquor. “Short” denoted a cheap car; “rubber,” a good one. “Bug disease” was when you let the irritations of daily life bug you, which he tried hard not to do. He considered himself a master of “skilapooping,” “the art of making what you’re doing look better than what you’re supposed to be doing.” Being “hip” meant “wearing hip boots, which means that he can walk through shit up to his ass, and not get full of it.”

Larry Tye is a Nieman Fellow at Harvard University and former journalist at The Boston Globe. He is the author of several books, including Satchel, Bobby Kennedy, and Superman