For TV and radio news stations, the first anniversary of the Sept. 11 attacks will be a nonstop blur of memorial events, emotional reminiscences and related news stories. Their challenge: Cover the occasion without bludgeoning it. Everyone else in radio and TV -- those normally devoted to playing cartoons, comedy shows or Kenny G songs -- faces a different challenge: Ignore the anniversary without seeming callous or mindlessly irrelevant.

Too much or not enough? Coolly dispassionate or exploitatively emotional? As the one-year anniversary approaches, the electronic media -- which served as a unifying presence for Americans in the hours and days after Sept. 11 -- are still wrestling with the question of the right balance.

"For all broadcasters, there's a real struggle to pay tribute but not be seen as exploiting it," said Kenny King, operations manager for "smooth jazz" station WJZW-FM and Mix 107.3, which plays upbeat contemporary music. "Everyone is still trying to work out what's the right thing to do."

The sheer volume of programming planned for the day by American media outlets is overwhelming, not to mention the subject matter.

The broadcast TV networks, assisted by their Washington affiliates, will carry all-day coverage of events in Washington, New York and Pennsylvania. So will the cable news networks -- CNN, MSNBC, CNBC and Fox News Channel. Anniversary programming of some kind will appear on a dozen other networks as well, from Discovery to MTV to Showtime.

National Public Radio, which plans nearly 24 hours of live coverage, has even commissioned special piano music to tie the day's events together.

The wall-to-wall coverage guarantees that the same themes and images will be played and replayed. Is America prepared to deal with terrorism? How has the country changed? Is it safe to fly again? How are the families of victims faring?

The inevitable emotional overkill has already been satirized by the spoof newspaper the Onion, which last week put up an American flag flying at half-staff surrounded by television network logos and the sarcastic headline "Who Will Bring Closure to a Grieving Nation?"

But one media researcher and critic said the media should stop worrying -- the public is eager to ritualize the events and emotions surrounding Sept. 11.

"It's not the amount of coverage that counts but the occasion it's devoted to," said Robert Lichter, president of the Center for Media and Public Affairs in Washington. "Journalists are more comfortable reporting facts than bearing witness. But at times like this they play a cathartic role in the life of the nation."

One jarring element is sure to be missing from much of the coverage: commercials. Most electronic media outlets decided weeks ago to ban ads from at least part of their telecast day. The nation's largest radio chain, Clear Channel, has banished ads for most of the day on its 1,200 stations, which include eight in the Washington area. The major broadcast networks expect to forgo tens of millions of dollars in ad revenue on Wednesday; a few programs may have sponsors, but otherwise there will be few if any commercials.

The decision was partly altruistic, partly for appearance's sake -- and also a recognition that many advertisers planned to take that day off.

"You can't get hurt by what you don't say," said Washington advertising executive Howard Bomstein, who has advised his clients to stand down on Wednesday. "So if you say nothing, no one can accuse you of commercializing a solemn holiday. The smartest thing to do is not advertise."

The lack of commercials, of course, means even more anniversary coverage -- echoing last Sept. 11, when stations went round the clock with news reports for nearly five days. With no lengthy commercial breaks, the reporters on WTOP-AM/FM, for example, will have seven more hours of air time available than they would in a typical 24-hour period. "We've been preparing for this for weeks," said WTOP News Vice President Jim Farley.

Not every channel will be draped in black: TV networks that specialize in entertainment will acknowledge the day in subtle ways, if at all.

E! Entertainment will rerun a series of documentaries about the TV shows "Cheers" and "Frasier." The significance: Both programs were produced by David Angell, a passenger on American Airlines Flight 11 when it crashed into the World Trade Center.

TV Land, which shows old network series, plans to reprise the famed "I H New York" commercials, but otherwise will stick to its regular lineup, which includes "Brady Bunch" and "Happy Days" repeats.

Kids' channel Nickelodeon will carry its usual shows, too, but will add a series of public service announcements offering children's reactions to Sept. 11 and tips on how parents can talk to their children about it.

Comedy Central, which stayed on the air with comedy programming on Sept. 11, 2001, will do so again.

"We learned a lot last year," said the cable channel's spokesman Tony Fox.

Viewers had "plenty of opportunities to get news coverage and information," he said, but "there weren't a lot of opportunities for people who couldn't or didn't want to see it to go somewhere else." This Wednesday, he added, "we can offer a safe refuge for those people. That's our overall thinking behind our plans."

With one exception: Jon Stewart's late-night "Daily Show," which did not air on Sept. 11 and did not return for 13 days, will also sit out the one-year anniversary.

Stewart's show makes fun of "what's in the news and how the news covers the news," Fox explained, and on Sept. 11 "the media was so consumed with coverage of the tragedy, there was nothing the show could work with other than that, and that was clearly inappropriate. On the anniversary, the almost exclusive topic in the news will be September 11th and we're not going to go near that."

With the exception of public service announcements honoring the occasion, other networks will ignore the occasion in their programming as well, remaining proudly irrelevant.

"We're a network about escapism," said Laurie Goldberg, a spokeswoman for the Cartoon Channel. "Basically, we feel it isn't appropriate to do anything." The network has looked over the cartoons scheduled for the day to ensure that there's nothing "evocative," but otherwise it's business as usual. Said Goldberg, "Last September 11, we got letters from parents and teachers thanking us for not mentioning what was going on."

And on some radio stations, the view is the same.

"This is a day for a different kind of entertainment," said Jeff Wyatt, program director of Hot 99.5, a Top 40 station that will stick to playing music but not ads. "We don't want to make the public relive one year ago. It's not our intention to relive horror."

That's the general game plan for Kenny King's jazz and pop stations as well. "We'll talk about it," he said, "but for the most part, we'll do our normal programming. We'll be ourselves."

Both Wyatt and King said they'll keep a close eye on what's played on Wednesday. They'll temporarily banish songs that set the wrong tone or message -- R.E.M.'s "It's the End of the World as We Know It," or Eminem's mother-hating "Cleaning Out My Closet," for instance. More likely to be played, they say, will be pleasant, uplifting songs such as Enrique Iglesias's nice "Hero," or Faith Hill's even nicer "There Will Come a Day."

Staff writer Lisa de Moraes contributed to this report.