Jamaican-born Millie Small, who recorded and performed simply as Millie, was the first artist to bring ska music out of the Caribbean and on to a global audience, starting in her adopted Britain and later in the United States and beyond.

Discovered and managed by the London-born Jamaican-resident music producer Chris Blackwell, her teenage success, though fleeting, paved the way worldwide for first ska, then rocksteady and later reggae artists such as another Blackwell discovery, the Rastafarian Bob Marley.

Although he said he hadn’t seen the reclusive singer in person for 12 years, Blackwell had been her guardian since she was a teenager, and it was he who revealed to the Jamaica Observer newspaper that she had died May 5 in London after an apparent stroke. “I would say she’s the person who took ska international,” he said. (She was variously reported to be 72 or 73.)

Ms. Small was a one-hit wonder — her lyrically shallow but catchy ska song “My Boy Lollipop” reached No. 2 in 1964 on both the U.K. and the U.S. Billboard charts, second to the Beach Boys’ “I Get Around.”

“My Boy Lollipop” sold 7 million copies, still one of the best-selling ska or reggae songs of all time. But a black female teenager with a near-falsetto voice singing electric Caribbean street music, rather than the gentle calypso of Harry Belafonte, was a new phenomenon during Britain’s “Swinging Sixties” dominated by the Beatles, Rolling Stones, Motown and Bob Dylan.

Ska music, which originated in Jamaica in the late 1950s, is usually defined by a “walking” bass line and an upstroke guitar chop on the off beat, known in Jamaica as the “skank,” a rhythm that a decade later metamorphosed into reggae.

When Ms. Small arrived in New York at John F. Kennedy International Airport from London in 1964, still in her teens, she received a rapturous welcome not far short of that given to the Beatles earlier that year. Thirty of New York’s finest had to bundle her through adoring, screaming and even dancing fans while newsmen, photographers and TV crews scrambled for footage or interviews. One fan presented her with what was described as “the world’s largest lollipop.”

Although her later recordings, and three albums, had only limited success, Ms. Small became an icon among Britain’s black community after she sang what is considered one of the country’s first-ever black protest songs.

In 1968, extreme right-wing Conservative member of Parliament and former cabinet minister Enoch Powell had made a fiery racist address that became known as the “rivers of blood” speech.

In one of the most divisive addresses in modern British political history, he called for a stop to immigration from Britain’s Commonwealth countries, particularly Africa and the Caribbean as well as the repatriation of those already in the United Kingdom. Referencing an ancient Roman quotation, he said he foresaw “the River Tiber foaming with much blood.”

The speech was still dividing Britons in 1970 when the pint-size dynamo Millie got onstage during a packed Caribbean music concert at London’s Empire Pool, since renamed the Wembley Arena and next to the Wembley soccer stadium. She sang a reggae song she called “Enoch Power,” which contained references to the Jamaica capital city of Kingston and to Powell’s former constituency, Wolverhampton.

“I arrived from Kingston Town . . . Got to go to Wolverhampton, help my brothers do a thing. They work all week to keep the British country running. Weekend it’s reggae time and the neighbors find it funny, so we all sing Enoch, Enoch, Enoch Power, Lord Lord.”

She had recorded the song only as the B-side of a single, but it had an empowering effect on Caribbean immigrants who had sailed to the U.K. after World War II after being invited by postwar governments to help rebuild the Commonwealth’s “mother country” after six years of war.

Millicent Dolly May Small was born Oct. 6, 1946 — although in some news reports she was actually born a year later — on a sugar plantation in the small spa town of Milk River. She was the youngest of 12 children of the plantation’s supervisor.

She was 12 when she won a high-profile talent contest, the Vere Johns Opportunity Hour. To pursue a singing career, she moved in with relatives in Kingston and recorded duets with some of the island’s top male ska musicians. Recording as Roy and Millie, she had a Jamaican hit with Roy Panton called “We’ll Meet.”

That brought her to the attention of Blackwell, who, with her mother’s blessing, became her legal guardian and took her to London to give her singing, diction and dancing lessons. Blackwell had founded a new record label, Island Records, as a 22-year-old in Jamaica in 1959, the label that would later introduce Marley to the world.

Blackwell produced and in February 1964 released “My Boy Lollipop,” which had been written by Bobby Spencer (latterly of the Harlem-based group the Cadillacs) and first recorded in 1956 by a 14-year-old white girl from Coney Island called Barbie Gaye to little acclaim.

Jamaican guitar maestro Ernest Ranglin made a new arrangement for Ms. Small. Pirate radio stations began playing it round-the-clock, and soon the wide-grinning Millie was appearing on some of the biggest British TV shows.

By the early 1970s, Ms. Small disappeared from public view and was believed to have lived in Singapore and New Zealand before returning to London for the rest of her life. She had a daughter, Jaelee Small, a London-based singer.

In a rare interview in 1987, Millie Small told London’s Thames TV channel that she had once been penniless in London, and that she and her infant daughter had lived for a time in youth hostel. “That’s all experience. It was great. I didn’t worry because I knew what I was doing. I saw how the other half live. It’s something I chose to do.”