Colin Moynihan for The New York Times.

Each year since 2008, members of the Industrial Workers of the World Starbucks Workers Union had demonstrated on Martin Luther King‘s Birthday, protesting that the company’s baristas who worked on the holiday were not given holiday wages.

On Monday, members of the organization held a roving demonstration in Lower Manhattan that they said was organized to celebrate Starbucks’ new policy to pay its employees – called “partners” by the company – time and half for working on the King holiday. Workers said that beginning Starbucks employees are paid around $9 to $10 an hour in New York, which is higher than the minimum wage in the state.

“It took three years to get time-and-a-half pay on Martin Luther King Jr. Day,” a Starbucks worker and group member who gave her name as Liberty Locke announced to the crowd in front of a Starbucks at Union Square East. “It took a lot of marches in New York City and a lot of actions in other cities, petitions, partner surveys, mission reviews, demand letters, calling and calling and calling.”

But Stacey Krum, a spokeswoman for the Starbucks chain, said the group’s campaign had nothing to do with the company’s decision to give workers holiday pay. “In November we announced we were adding M.L.K. Day as a holiday,” she said. “It is one of the most requested by our partners.”

The World Starbucks Workers Union members, who have been waging a campaign against Starbucks since 2004, asserting that the company has unlawfully prevented workers from unionizing, didn’t just take “yes” for an answer. They seized their moment in the media spotlight Monday by staging a demonstration reminiscent of an earlier era of labor activism, announcing that several Starbucks workers had just joined the Industrial Workers of the World, also known as the Wobblies, which was a powerful far-left labor union a century ago.

After about 40 minutes on the east side of Union Square, a crowd of about 65 people relocated in front of a Starbucks at Union Square West. They waved banners (“Demand Union Made Lattes”), chanted slogans (“Hey, he, ho, ho, exploitation has got to go”) and danced on the sidewalks. A band called the Rude Mechanical Orchestra played marching songs, polkas and a version of the Internationale that one band member referred to as “a dance remix version of one of your favorite standards.”

Eventually, the crowd marched south. They ended up at the Astor Place Starbucks, where eight of that store’s workers presented a letter to an assistant manager declaring membership in the I.W.W. and presenting a list of demands. Those included a raise of $1 dollar an hour for all Astor Place workers, “fair performance reviews,” a voice for employees in determining schedules and day-to-day operations, and a monthly meeting run by workers to air grievances and share ideas.

The letter also demanded the rehiring of two workers, one in New York and the other in Omaha, Neb., who the protesters said were unfairly fired.

“I’m actually hoping just for a store discussion,” said Cason Bolton Jr., one of those who signed the letter. “I want all the workers to be able to say how they feel.”

Ms. Krum, the company spokeswoman, said that the Astor Place management would look at the letter submitted there on Monday and talk with the employees. But she said neither the New York nor the Nebraska worker was fired unfairly.