The foothills of the U.S. Capitol: The music is loud. The food extravagant. The decor patriotic. The view overwhelming. The metal detectors annoying.

The nation's newest newspaper is launched. The president of the United States is coming any minute.

But first:

Why did USA Today lead the front page of its inaugural edition yesterday with news of Princess Grace's death when virtually every other newspaper gave greater prominence to the killing of Lebanese President-elect Bashir Gemayel?

A klatch of reporters waits patiently under a huge red, white and blue tent in front of the Reflecting Pool to ask the question of Al Neuharth, chairman and president of Gannett Co. Inc. and father of USA Today, which calls itself "The Nation's Newspaper."

Answer: Because Al Neuharth wanted to.

"Al did his own survey," explained executive vice president Vincent Spezzano, standing under a bouquet of red, white and blue balloons. "He asked around town, different people. He asked me. At the story conference he said that he thought that Princess Grace was the most important story in the minds of the people . . . That's what the paper's all about--figuring out what people out there are interested in."

USA Today hit town yesterday with flourish. The press run was 250,000, and circulation executives said the little blue and white boxes all over the city were sold out by mid-morning. During the day, Cabinet members, White House aides, congressmen and reporters were hand-delivered copies in bright silver envelopes. And by dusk, 800 showed up to celebrate the launching of a major newspaper when many think print is a dying medium.

Al Neuharth arrived with a flourish. The press klatch pounced.

"Well, not everybody led with Gemayel . . . we didn't," declared Neuharth, often referred to as either a publishing genius or a newspaper czar. He wasn't much up for chatting.

How do you feel today, another reporter asked him.

"Great."

Are you excited?

"Yes."

Are those little G's on your jacket for Gannett or Gucci, inquired yet another reporter.

"Well, it's not a company jacket," said Neuharth, inspecting his black silk Gucci dinner jacket through his tinted aviator sunglasses. "You figure it out."

"It's Gucci," sighed a public relations person. "Do you have to use that?"

6:15: No congressmen in sight. "How can you give a party for Congress when they don't show up?" inquired someone wearing a Gannett pin. "They're still voting," he answered himself.

6:30: No sign of the president yet. Sen. Ted Kennedy (D-Mass.) arrives in an unusual state. Alone. He shakes a few hands. It is not a typical Candidate Kennedy Welcome. Someone yells out, "Senator, what do you think of the paper?"

"Great!" booms the senator, disappearing into the crowd, voice fading. "I haven't seen it today . . . Just got back from Massachusetts . . ." Everyone seemed to be looking for Kennedy the rest of the night, but no one found him.

6:45: Senate Majority Leader Howard H. Baker Jr. (R-Tenn.). House Speaker "Tip" O'Neill (D-Mass.). Congressmen. Senators. Journalists. Attorney General William French Smith.

The president arrives for 15 minutes and the tent gets very hot and crowded. Flashbulbs pop. After a few campaign-style jokes, Reagan gets down to serious praise, wishing Gannett luck and success.

"I think I can say for everyone in the administration that you have our best wishes and we'll be rooting for you," he said.

7:05: The president is gone and the crowd is thinning. A distinguished-looking man, a milky-skinned aide to Rep. Ed Markey (D-Mass.) and a reporter are standing near a pillar draped in red, white and blue, a few inches away from the crab claws, fettuccine, roast beef and Vietnamese spring rolls. Popcorn and hot dogs are nearby.

Hill aide: "With a spread like this, I guess USA Today is a conservative newspaper."

Older man: "Why would you say that?"

Hill aide: "This is supposed to be a national newspaper, for everyone in the country. With all this exotic food and the state of the economy the way it is, how can they honestly take the pulse of America?"

Older man: "I disagree. The idea is to attract attention and make an impression on the power structure of Washington. They don't want to come in like some country cousins."

Hill aide: "Well, I liked the newspaper better than the spread. I still think it must be conservative."

Reporter to Hill aide: "This is Richard Viguerie. He does direct mail for all the conservatives."

Hill aide with hand to his head: "Oh no."

7:30: The Dixieland band interrupts "Yankee Doodle Dandy" to make an announcement. The brightly lit Capitol dome is behind them. Spectacular.

"Excuse me, for all of you congressmen here: There is a vote in 10 minutes. There is a vote in 10 minutes."

Everyone got vanilla ice cream on the way out.