If someone asked you to explain jazz, you’d probably start and stop a few times. Maybe you’d say something like “it’s improvised” or “kind of like blues but more…” and then trail off. That’s not a failure on your part. Even the word itself resisted definition for over a century. The American Dialect Society named “jazz” the Word of the 20th Century, which feels right, because the music it describes doesn’t sit still long enough to be pinned down.

April 30 is International Jazz Day, a celebration that now spans more than 190 countries. This year’s global host city is Chicago. Before we get there, here’s how it actually started.

The Word Itself Is a Mystery

The word “jazz” doesn’t come from New Orleans. The earliest known printed use shows up in an April 1912 Los Angeles Times article, where a minor league baseball pitcher described a pitch he called a “jazz ball” because, as he put it, “it wobbles and you simply can’t do anything with it.” By 1915 the word was being used for music in Chicago, and it spread fast from there.

Duke Ellington, Max Roach, and several other Black musicians who created the genre consistently said the music was named “jazz” by white Americans, not by the people who invented it. Researchers have confirmed that’s likely true. The musicians themselves often called what they were playing “ragtime” or variations of it. They first heard “jazz” coming from up north.

Composer Eubie Blake, who lived to 100 and played ragtime in Baltimore as early as 1898, reportedly refused to say the word “jazz” in polite company for most of his life because of its rough connotations in the early 1900s.

Congo Square and the Law That Made Jazz Possible

In the early 1800s, New Orleans operated under French colonial law, which permitted enslaved people to gather and play music on Sundays at a place called Congo Square. Most of the American South had no equivalent.

West African rhythms, Caribbean music from the West Indies, church spirituals, street brass band sounds, and Creole folk styles all came together in that one space, week after week. The call-and-response patterns, the polyrhythms, the improvisational spirit were all getting worked out there, publicly, decades before anyone called it jazz.

Other American cities had large enslaved populations and didn’t produce jazz. The gatherings weren’t allowed. New Orleans had that opening in the law.

The First Jazz Record and a Musician You’ve Never Heard

The Original Dixieland Jazz Band recorded what’s generally considered the first jazz record in 1917. Their members were white, which has made the historical record complicated, since the music was created by and within Black communities. The recording did spread jazz to audiences well outside New Orleans.

Most historians point to a cornet player named Buddy Bolden as the first actual jazz musician. He led a band in New Orleans in the early 1900s, improvised over ragtime and blues, and was by all accounts astonishing live. No recordings of Bolden exist. He was committed to a psychiatric institution in 1907 and never played publicly again.

Jazz Gave You More Than Music

You also use jazz vocabulary every single day without knowing it. The word “cool” as a general term of approval came from jazz, popularized by tenor saxophonist Lester Young in the late 1940s. “Gig,” meaning a work engagement, came from musicians picking up dates in the 1920s. “Cat,” meaning a fellow, came from the jazz scene. “Corny,” “schmaltzy,” even the phrase “all that jazz” as shorthand for “et cetera” all trace back to this music.

Prohibition, Speakeasies, and Al Capone’s Tips

Jazz came up in speakeasies. During Prohibition, those clubs operated outside the law, which also meant they operated outside the segregation norms that governed most public spaces. The “black and tan” clubs of the era drew racially mixed crowds in ways that nearly no other venues did.

Al Capone, who ran much of Chicago’s organized crime operation during that period, was apparently a reliable employer of jazz musicians. The pianist Earl Hines recalled that Capone liked to come in with his crew, call out requests, and tip a hundred dollars a song. The singer Ethel Waters said he treated her with respect and always paid in full.

International Jazz Day and Why Chicago in 2026

UNESCO designated April 30 as International Jazz Day in November 2011, and the first official celebration happened in 2012 with events in Paris, New York, and New Orleans. The idea came from jazz pianist Herbie Hancock, a Chicago native who serves as a UNESCO Goodwill Ambassador for Intercultural Dialogue. It took until 2026 for Chicago to host.

When King Oliver brought his Creole Jazz Band to Chicago in 1922, featuring a young Louis Armstrong on trumpet, it effectively started the Chicago jazz era. The All-Star Global Concert on April 30 streams live from the Lyric Opera House, and events are running throughout the month across Chicago’s neighborhoods.

If you want to dig in closer to home, the Black Hills doesn’t have a dedicated jazz venue, but Rapid City has seen occasional jazz programming through the Dahl Arts Center and the South Dakota Symphony’s jazz-adjacent events. You’ll also occasionally find smaller venues downtown that feature local jazz singers and musicians. 

Buddy Bolden, the man most historians credit with starting all of this, died in that Louisiana psychiatric institution in 1931. Nobody recorded him. Nobody wrote down his compositions. The music he made exists only in the memories of people who heard it, passed along in interviews decades later. That’s where jazz came from.