The list of performers paying tribute to the victims and heroes of the Sept. 11 terrorist attacks includes Placido Domingo, Gloria Estefan, Renée Fleming, Aretha Franklin, Al Green, Enrique Iglesias and Alan Jackson. But executive producer Jerry Kupfer ("The Mark Twain Prize") said the lineup would be subject to change between now and Sept. 9, when the show is taped.
"People want to change a song," said Kupfer, "or someone you really wanted comes on, or someone drops out."
Kupfer said he is trying to retain enough flexibility up to the last possible minute to accommodate what he called "AAA artists" who might want to participate in the special.
"If any one of those came around in the last couple of days we would open the waters up and try to get them in," he said. "It's being done at the (Kennedy Center) concert hall, which is a small stage. That means it's pretty flexible."
Although the concert will feature lots of music, Kupfer said he doesn't look at it as a variety show.
"I think overall it will feel like a music show," he said, "but when I look at a rundown of the show there's a lot of pieces we have, people doing readings -- Emily Dickinson, Walt Whitman, Martin Luther King Jr., and FDR speech or JFK. We have (film) packages. Some of them are letters from children read by children, accompanied by pictures of children, telling it through their eyes."
Kupfer said he hoped the end result will feature a representative variety of "arts and humanities" from U.S. culture.
"It really kind of expresses to a certain extent the unity of Americans coming together to take care of each other, celebrate America and kind of console each other," he said.
Kupfer said it will be a major challenge to come up with a program that strikes an appropriate tone for the occasion.
"Every single thing we do we have major considerations of, is this the right tone?" he said. "Unfortunately, you're never going to please everybody. Whether it's conservative-liberal, peace-military, whether it's more joyous, or does someone who had a loss really want to see that?"
Asked whether the White House was exerting much control over content, given the participation of the first lady, Kupfer said Mrs. Bush's staff has given "some good suggestions" but has not been "overtly involved" in putting the show together.
"I might get a note or two after they've seen some of the productions," he joked. "It is different than just putting on a rock 'n' roll concert where there's no political or historical considerations, or you're not dealing with a date where you have to be concerned with the tone."
On the other hand, Kupfer said the project has a lot in common with specials he has produced for CBS and MTV.
"You know, 'I could have this act on MTV but it's not going to work well on CBS,'" he said. "Obviously, whatever kind of production you're doing. One obviously knows what's appropriate and what isn't."
Kupfer said it would be impossible to know until the day of the taping exactly what tone the show would set.
"We're all waiting to see how people feel on that day," he said. "I think it's kind of a day that people will see as a mourning. I think we're taking an approach of showing somewhat of a brighter side -- you won't walk alone, we have a great country -- certainly looking at this in a more positive way. Certainly, there's going to be a lot of programming (on Sept. 11) which will take a different approach. I think everything has a strong place. This show is to say we're going to let freedom sing, so to speak."
The National Symphony Orchestra, conducted by Music Director Leonard Slatkin, will perform a few selections. NBC News anchor Tom Brokaw will host the special.