In 1969, jazz trumpeter Miles Davis released his seminal fusion album Bitches Brew. The record was revolutionary, from its experimental sound to its psychedelic cover art steeped in free love and flower power, to its striking, even shocking, title. What exactly that title means, though, remains a mystery. Over the years, many theories have circulated, but none have settled the debate.

Without an apostrophe at the end of the plural noun Bitches, some have speculated that Brew was meant as a verb, not a noun, as in “a thing that bitches do, is brew.” Given the album’s cover theme, the title might suggest brewing a potion for voodoo possession or concocting a mixture used to create zombies. Guitarist Carlos Santana offered a different interpretation, suggesting that the album was a tribute to the “cosmic ladies,” Davis’s wife Betty and her friends, who surrounded him at the time and introduced him to the music, fashion, and spirit of the 1960s counterculture. Whatever the title meant, it was provocative, just like the music itself.

Yet the term had a rich history in the argot of jazz musicians, long before Miles Davis gave it new life.

At the turn of the twentieth century, jazz pianist Jelly Roll Morton composed some decidedly raunchy blues numbers that he performed in the Storyville saloons and brothels of New Orleans. These included his racy “Murder Ballad” and a bawdy version of Mississippi John Hurt’s “Make Me a Pallet on the Floor.” (Curious readers can look up the explicit lyrics for themselves.) Morton was a piano player, an instrument considered “feminine” at the time, so using the “smutty” word helped shore up his tough-guy cred.

The word also has roots in the “dirty blues,” a subgenre of blues that tackled taboo topics like sex and drugs in blunt, often obscene lyrics. Singers such as the “Mother of the Blues,” Gertrude “Ma” Rainey, along with Bessie Smith and Lucille Bogan, used the term as a form of empowerment in an industry dominated by men. These were early acts of linguistic reclamation, women turning a word meant to demean them into one that asserted confidence and control.

As for the infamous title of Bitches Brew, others have suggested that the “bitches” were the artists themselves, since the term was once a compliment for a highly skilled jazz musician.

A musician who was really “hot,” a master of their instrument, was traditionally referred to as a bitch. Davis often used the word this way, both for himself and for fellow players he admired. In his memoir of the 1930s jazz scene, Mezz Mezzrow recalled a gifted cornet player named Yellow: “That boy was really a bitch, even though he was never taught to play music. He had more music in him than Heinz has pickles.” Decades later, Crescendo magazine echoed the same sentiment in an article about jazz bassist George Duvivier: “That’s one of the greatest bassists of all time on there. Very underrated—but he is a bitch, believe me.”

In the language of jazz, bitch meant something else entirely: someone talented, gifted, and effortlessly cool.

With the word’s seal of approval from none other than Miles “Prince of Darkness” Davis, other musicians began using it too, from the Rolling Stones and David Bowie to Elton John. It soon became part of the language of pop, and later, of rap and hip-hop. (But that’s a story for another time.)

Still, while the word has been reclaimed in some contexts, it remains an insult in others—a reminder that language, like music, can shift key, but never entirely change its tune.

Dr. Karen Stollznow is the author of On the Offensive: Prejudice in Language Past and Present and her latest book is Bitch: The Journey of a Word.