SEOUL, South Korea >> Jokes and concerts are out. So are school field trips and boisterous cheering at baseball games.

As South Korea mourns one of its worst ever disasters, a ferry sinking on April 16 that will likely result in the death of more than 300 people, most of them high school kids, anything deemed frivolous or fun is frowned upon, and the backlash for breaking this collective somber mood can be harsh. 

A politician has been warned by his party for attending a party where alcohol was served, another was criticized for running in a marathon. A popular singer has been lambasted online for going ahead with a concert as the bodies recovered from the sinking mount.

“It’s not the right time to sell joy and laughter,” Maxim Korea, a popular lifestyle magazine, said in an online message announcing it would withhold publishing its May issue.

Most of the jocular, wildly popular comedy, reality and talk shows that usually fill the airwaves aren’t even filming, much less appearing on TV, replaced by somber documentaries or near-constant news coverage of the sinking.

Springtime flower festivals have been canceled across the country. The Education Ministry has ordered many schools to cancel field trips until July. Musicians have postponed album releases. Broadcasters have scrapped live K-Pop shows.

Baseball officials have asked professional baseball teams’ cheering squads to refrain from cheering loudly and to keep the usually ubiquitous female cheerleaders from the stands and field.

Movie attendance has plunged, according to the Korea Film Council’s box office count. And radio listeners are noticing markedly different playlists on their favorite channels.

“DJs are playing sad music most of the time,” said Hong Yeo-tack, a Seoul taxi driver who listens to more than 10 hours of radio a day while driving.

South Korean entertainment company CJ E&M has canceled most of the entertainment shows on four of its cable channels and won’t show any disaster films “out of respect for the ferry tragedy and the period of mourning we’re experiencing as a nation,” said international PR manager Joe Yoon.

Many South Koreans agree with the unofficial moratorium on fun.

“The band made the right decision,” Hwang Ji-hye, a 27-year-old yoga instructor, said of popular South Korean group Jang Ki-ha and the Faces’ last-minute cancellation of a concert she had tickets to. “Both the singer and the audience would have been heavy-hearted had the concert gone ahead.”

To ease the national grief, college students are encouraging people to wear yellow ribbons — a custom borrowed from the U.S. to express hope that the missing will return — and change their online profile pictures to include yellow ribbons to support victims. 

But there is also an aggressive online effort to shame those who are seen as acting insensitively. 

Web users criticized Lee Sun-hee, a 49-year-old entertainer dubbed “The “Diva of Korea,” for going ahead with three days of concerts to mark the 30th anniversary of her debut. Local media reported that Lee’s company said that canceling would hurt thousands of staff and audience members and that the concerts would be a tribute. But most of the online response was that she acted inappropriately and should’ve donated part of the proceeds to rescue efforts. 

When the captain of the Lotte Giants’ cheering squad, Cho Ji-hun, apologized on Twitter after widespread criticism following his loud performance of the baseball team’s “Boat Song,” Twitter users called him a “psychopath” and asked, “Do you have a brain?”

Yu Han-sik, a ruling Saenuri Party member who’s running for a mayoral seat in Sejong city, was warned by the party’s ethics committee for attending in a dinner banquet where alcohol was served two days after the sinking. Yu denied drinking alcohol.

Rep. Lim Nae-hyun was condemned for running in a road race only four days after posting on his Twitter page that he is “praying for the missing students to be rescued.” People online questioned his sincerity; even his fashion choice — a brightly colored top and a name tag stating that he was a lawmaker — was seen as inappropriate self-promotion. 

After more than a week of blanket coverage of the sinking, however, some say they wouldn’t mind some escapist entertainment. 

“My heart goes out to the students, but I’m getting a headache after days of seeing nothing but miserable news,” said Sohn Soon-ja, a receptionist at a Seoul bathhouse whose counter is near a TV screen. 

News assistant Wonju Yi contributed to this report from Seoul.