WASHINGTON >> The after-dinner playlist is set. The garden herbs have been harvested. The tweeple are on their way.

Thursday’s White House visit by South Korean President Lee Myung-bak, the fifth state visit of the Obama administration, features a new category of guests.

The morning arrival ceremony, with its heavy dose of South Lawn pomp and ceremony, always is a sought-after ticket.

The higher-octane state dinner still is the ultimate black-tie invitation in wonky Washington.

But this state visit also will include a “tweetup,” an in-person meeting of people who use social media such as Twitter and Facebook, offering participants — tweeple — a chance to attend and live tweet the arrival ceremony for the leader of one of the most wired nations on earth.

It’s just one more way for President Barack Obama to make a grand show of hospitality for his South Korean guests at the first White House dinner for the country since 1998. The two leaders hit it off during Obama’s first trip to Asia in 2009, and have been allies on a number of key issues.

If congressional approval this week of a long-awaited free trade agreement with South Korea is expected to be Lee’s big-ticket takeaway from his visit to the United States, the personal chemistry and friendship cemented amid all the accoutrements of a state visit are an intangible but equally important element. There will be plenty of one-on-one diplomacy crammed into the social schedule: Obama and Lee will take a joint field trip to Michigan on Friday to visit an auto plant, and Michelle Obama and South Korean first lady Kim Yoon-ok on Thursday morning will visit Annandale High School in suburban Virginia, home to a large Korean-American population. 

State dinner details — the menu, entertainment, guests — are generally a closely guarded secret until the last moment. But details are trickling out, in some cases from the White House itself.

When Mrs. Obama invited in school kids last week to help harvest the kitchen garden on the South Lawn, she let it be known that some of the vegetables and herbs were destined to pop up on the state dinner table Thursday night. No word yet on whether it will be the sweet potatoes or the squash, the peppers or the basil.

The after-dinner entertainment will include a group tailor-made for the event — the Ahn Trio, three sisters who were born in Seoul but reared in the United States.

Angella, Lucia and Maria Ahn, who tweeted about their upcoming White House gig, play violin, piano and cello in a musical style that they describe as classical-alternative-experimental.

Angella, on the faculty at Montana State University, told the university they’ll play “Skylife” by California-born David Balakrishnan and two pieces by Argentinian composer Astor Piazzolla. Balakrishnan has described “Skylife” as a “slow burning, heavy-metal grinding kind of number. If this were the ‘60s, the comparison would be to Led Zeppelin.”

A few names from the various guest lists were trickling out, too.

San Antonio Mayor Julian Castro is a state dinner natural: He’s cutting short a trade mission to South Korea to attend the dinner with his wife, Erica.

ABC’s Juju Chang, who also got the coveted nod for a seat at the dinner, modeled 10 possible gowns on ABC’s blog and asked readers to vote on what she would wear. 

Adam Frankel, a student at George Washington University, snagged a ticket to the tweetup after seeing a post about the event on the White House Facebook page. He confessed he doesn’t have any special interest in South Korea, but says he’s interested in technology — “and I’d very much like the opportunity to meet the president.”

Other tweeples were atwitter on Twitter this week about what to expect at the White House, what to wear and what the weather will be like. They were getting a chance to prep their thumbs at a tweetup happy hour on Wednesday night.

At mid-week, David Lee, president of the Korean American Public Affairs Committee, still had his fingers crossed: He’d been invited to the morning arrival ceremony but still was holding out hope for a dinner invite.

“I tried, but I didn’t get an invitation — yet,” he said.

For those who don’t make any other invitation lists, there’s one that’s open to anyone: A group protesting the construction of a naval base on a South Korean island is asking people to protest in front of the White House during the dinner.