The Big Apple Barbecue Block Party is the kind of event that sends certain New Yorkers into a twitchy state: Those who have been to the event launch into an impassioned speech about their favorite vendors and cuts of meat. Those who haven’t take on a look of longing and hopefulness at the mention of this annual festival.

Last year, 120,000 people crowded Madison Square Park and the surrounding streets to taste South Carolina whole roasted pig, Texas smoked beef brisket, Alabama pulled pork, and Kansas City ribs — made by a New York pit master.

This year’s festival will likely draw a similar crowd for the food, as well as the talking about food: Seminars about barbecue culture will include authors Jeffrey Steingarten, Calvin Trillin, John T. Edge, and Ed Levine, and a 20-year veteran food editor for the Observer in Charlotte, N.C., Kathleen Purvis.

Ken Callaghan, the executive chef of Blue Smoke, was a part of the first block party in the spring of 2002. At the time, the event was only one block long — stretching down 27th Street between Lexington and Park avenues, in front of Blue Smoke. “We closed off the one block in front of the restaurant, and it was pouring rain,” he said in an interview last week. “And still, 10,000 people showed up.”

Mr. Callaghan doesn’t come from traditional grilling stock: Before his barbecue assignment, he worked as the executive chef at Danny Meyer’s first fine dining establishment, Union Square Café. Mr. Meyer, a native of barbecue-friendly St. Louis, wanted to build a restaurant in New York that could showcase a regional span of the nation’s barbecue culture — from Texas brisket to Memphis baby back ribs. The city immediately responded, with barbecue lovers coming to the restaurant for a taste of whatever hometown they came from — and with plenty of words for the chef about different regional styles. “We learned about the New York melting pot,” Mr. Callaghan said, recalling the restaurant’s opening, which also took place in 2002. “People who knew one kind of barbecue would try another kind and say, ‘Hey, that’s not barbecue.’ If you didn’t cater to them, they didn’t like it.”

The first festival served as a regional tutorial for anyone who didn’t know about the state and city differences among styles of barbecue. Participants included Mr. Callaghan; Rick Schmidt of Kreuz Market in Lockhart, Texas; Chris Lilly of Big Bob Gibson Bar-B-Q in Decatur, Ala.; Ed Mitchell of the Pit in Raleigh, N.C., and Mike Mills of 17th Street Bar & Grill in Murphysboro, Ill. These men might not be household names in the city, but for barbecue aficionados, they are powerhouses. Each is known for innovative cooking methods; and in the case of Messrs. Mills and Lilly, also for being winners of the Memphis in May competition, which is the Super Bowl of smoking and grilling. Messrs. Mitchell, Mills, and Lilly are all returning for this year’s festival.

Despite the influx of pit masters from around the country (even Los Angeles is represented, with Jonathan Burrows of Mr. Cecil’s serving beef ribs), New York establishments are in full force. Former line cook at Blue Smoke Pete Daversa, who has been the pit master and executive sous chef at Hill Country on West 26th Street for the past six months, will be behind his own rig for the first time at the festival this year. He will be serving “hill country”-style beef ribs, modeled after barbecue from central Texas that’s seasoned with nothing but salt, pepper, and cayenne.

Mr. Daversa got his first taste for the block party as a supporting cast member of the Blue Smoke team in 2004. “I had no idea about the festival then,” Mr. Daversa said. “It was a total culture shock.”

Even though he wasn’t familiar with barbecue culture at the time — and he is now, having traveled to Mr. Schmidt’s Kreuz Market in Lockhart, the heart of American “hill country” — Mr. Daversa notes that many city residents come into his restaurant with an impressive grasp on the intricacies of barbecue. “New Yorkers are knowledgeable,” he said. “Every barbecue culture has been brought here.” Other city restaurants that are participating in the block party include John Stage’s Dinosaur B-B-Q (pulled pork shoulder) and John Wheeler’s Rack and Soul (baby back ribs).

Mr. Callaghan noted that city dwellers aren’t the only ones excited about the block party, citing the pit masters’ own interest in participating. “They’re here to show off their craft,” Mr. Callaghan said. “We bring the elite here. It’s a wonderful thing.”

Saturday and Sunday, noon-6 p.m., Madison Square Park, between Fifth and Madison avenues, from 23rd to 26th streets, 646-747-0584, free. Each plate of food is $8. Sides are $4. All seminars and music events are free. For complete information, go to bigapplebbq.org.