Before the bongos and bagpipes and Bolivian dance music took over the center of Rockville for the city’s 70th annual Memorial Day parade, a nervous database employee of the Federal Aviation Administration stood before the assembled veterans and politicians and babies on shoulders and took a breath.

Len Morse makes his living as an aeronautical information specialist. But on a brilliant, sunny day filled with celebratory fire engine sirens and drum corps rhythms bouncing through Rockville’s booming downtown, it was Morse’s job to play taps. He’s been doing it for years, but it hasn’t gotten any easier. He tells himself how short it is, which “helps with the confidence factor,” he says. Mostly, he tries to manage the pressure with concentration.

“Part of me focuses on each note and making as pure a sound as I can,” Morse said, “and the other part of me focuses on why I’m there in the first place. Just the thought of paying tribute helps.”

Morse and his trumpet anchored Rockville’s intimate Memorial Day commemoration with a somber melody heard in communities large and small across the nation Monday. At Arlington National Cemetery, President Obama placed a wreath at the Tomb of the Unknowns and in a speech singled out relatives of those lost in war — from a woman who waited 63 years for her husband’s remains to be located in Korea to a group of young siblings sitting with first lady Michelle Obama.

“Your parents’ bravery lives on in you,” Obama said. “You will never walk alone. Your country will be here to help you grow up into the men and women your parents always knew you would be.”

Elsheba Khan, 53, lost her only son — Cpl. Kareem Rashad Sultan Khan — in Iraq in 2007. She spent Monday at Arlington, gazing at Kareem’s epitaph and the sky.

“It has been seven years, but I’m still grieving,” she said. “He was always there for me. If anything happened, the first person I called was him. Things still happen and whenever I pick up the phone to call, he is not there.”

But it was along neighborhood streets and in modest parades where many shared their memories of the fallen. Moments after Morse’s final note in Rockville, William S. Campbell, who faced fire in Vietnam while serving in the Navy and has lived in the same Rockville home with the same phone number for 42 years, tried to explain the power of this day.

“I’ve got so many friends — ” Campbell started. But he choked up and couldn’t finish and finally just quietly repeated the word “friends.”

He headed off to serve as the parade’s grandmaster, riding beside his son Wesley Campbell, who served in Iraq.

“My dad served in combat. That’s how it comes about,” William Campbell said. “Teeth knocked out and broken bones and land mines and machine guns. It’s just like the movies. You get scared as hell and you do your jobs.”

Wesley, a Navy officer, said that today in America, “an even smaller proportion of our society serves in the military. There are very few opportunities for people to reach out and interact with people who serve. I think this is one of the best days to do it.”

It was a notion echoed in the District, where Geoff Oravec, an active-duty Air Force member, and his partner, Phil Nguyen, watched veterans and high school bands marching along Constitution Avenue.

“I think it’s actually good that a lot of people here aren’t in the military,” Nguyen said. “Otherwise, it’s really growing apart, civilians and military.”

Families with generations of military ties joined tourists from Texas and Australia lining Washington’s sidewalks. “Our family has fought in every single major American war,” said Phillip Miller of Crofton, who served in the Army for 22 years and came with his grandfather, J.W. Fleming, a World War II veteran. They fell silent and raised their hands in salute to the Sons of the American Revolution members as they marched past.

“Washington always does it right,” Miller said.

And for 70 years, Rockville has had a parade that has maintained its down-home feel even as the city has grown.

“I think of Rockville as a city with a small town inside of it,” said Robin Wiener, who brought her son Sammy, a first-grader at St. Mary’s Catholic School. “I come every year. It’s great for our town.”

Towering above Wiener as she spoke was a massive red crane, part of the construction transforming the city’s center with new office buildings, apartments and a hotel. But it all still feels familiar, she said. From the 15th floor of the office building where she runs an electronic medical records business, “you can see St. Mary’s and behind it you can see our house. That’s pretty awesome as a mommy.”

Trish Gallalee, a member of St. Mary’s Church, headed down the parade route with her service dog, Indy, wearing a red, white and blue bandanna, and a scale replica of the church with a little bride and groom on the porch. The homemade props — including the Cub Scout-crafted rolling wooden tank — are part of the charm, she said.

Many years ago, “we had the Clydesdales here. They were like, ‘This is too small-town for us,’ ” Gallalee said. Her answer to that? “You made a lot of people happy.”

What made soccer coach Andres Moreno and his daughter happy were the Bolivian dancers in the red, white and blue sequins — the women with bowler hats, the men carrying cowboy hats. His father served in the 1991 Persian Gulf War, and seeing the World War II veterans moved him, as did watching the diversity of his home town of 13 years.

“I wouldn’t live anyplace else. I’ve traveled all over the U.S. There’s no other place like Maryland. It’s beautiful,” he said, though he acknowledged that some “people are going to disagree with that.”

At the end of the route, Vihaan Kumar, 5, plastered with political stickers from a stream of office seekers, climbed on a Rockville police officer’s motorcycle for a photo, part of the Memorial Day his parents wanted him to experience.

His father, Azad Kumar, works on vaccines at the National Institutes of Health, and his mother, Priyanka Tyagi, is a homemaker. They are both Indian citizens, but their son was born in the United States.

“He should learn to respect soldiers,” Tyagi said, and learn that American service members risk themselves for countries such as Afghanistan, not just the United States.

“He was born here. So he should know everything,” Kumar said.

Vihaan’s favorite part? “The police,” he said. “It’s so fun.”

Harry Misiko, David A. Fahrenthold and Antonio Olivo contributed to this report.