RIO DE JANEIRO (AP) — One day over lunch in Serbia three years ago, Kim Hill began yodeling.

She is quick to downplay her talents for a practice rooted in the Alps. She insists it's just a song she learned growing up that happens to include yodeling.

Regardless, her teammates and coaches absolutely love when she does it, even if yodeling is not on the Olympic program.

"I don't know how to actually yodel, definitely never took lessons," Hill said. "Growing up, my family went to this German restaurant every year and there's a song they sing there that has some yodeling in it."

However the story goes, there's one thing most everybody agrees on: That first yodel marked the moment Hill fit right in with U.S. women's volleyball team and a group drawn to the spontaneous.

A song. A dance. An improvised cheer.

The way U.S. assistant coach Tom Black remembers it, the players were talking over their meal and Hill mentioned yodeling. Of course, they begged her to demonstrate.

"And it caught on real fast," Black said. "There was a lot of yodeling going on by the group and it was tradition for about a year and a half. I was laughing and also really happy for Kim. She was the new kid on the block, and the way she handled it — self-effacing, having fun but willing to laugh at herself — and the genuine enthusiasm the veterans showed about it helped them coalesce into a tighter group. I was more encouraged for that aspect of it. There was never a problem before, but I think that was the moment Kim was officially in."

So, how's that saying go? For this group, the team that yodels together wins together.

That remains to be seen for the unbeaten and top-ranked U.S. squad, which is chasing its first Olympic gold medal and topped rival China in four sets Sunday night. The Americans won 22-25, 25-17, 25-19, 25-19.

Coach Karch Kiraly knows he has an immensely talented, family-first roster. The most decorated player of his generation and only person with gold in beach and indoor volleyball has embraced the quirky moments along the way. Whatever it takes to build a unit that will stick together in pursuit of the top prize in Rio.

"It's different than coaching a men's team. Sometimes the women's team will just be at lunch and break out in song," Kiraly said. "And I'm OK with that, I think it's awesome. They'll just break out and start dancing, like we'll be warming up in the warmup gym and they'll start dancing a little bit. We love to play our music, they love to dance, they love to sing. And I love that they are in an atmosphere where they feel they can be themselves and do that and break into a dance if they feel like it. So, Kim, they all have the freedom and the trust and the safety to do that."

After that first yodeling show came Kiraly's 53rd birthday four months later on Nov. 3 during a tournament in Japan. Of course, Kiraly requested a celebratory yodel from Hill for the occasion.

"We love throwing twists on the traditional 'Happy Birthday' song, so yodeling was what Kim threw into the mix," captain Christa Dietzen said. "Each of our younger teammates all had to find their role or place on the team. It takes a while, but the culture we've created allows people to be all of themselves."

The soft-spoken outside hitter from Portland, Oregon, has been a regular Olympic starter so far. Don't let her demeanor fool you.

"She has got the most amazing spirit about her. Nothing fazes her," Kiraly said. "I don't know anybody in this world who could find a bad word to say about her. She's just a sweetheart. And I think that fools some people. I think that sweet exterior makes people think that she might not be very competitive, but she's extremely competitive in her sweet way."

Assistant coach Jamie Morrison is sure the 6-foot-4 Hill should take the yodeling lead.

"I have attempted to join in but my yodeling skills are not up to par with Kim," he said, noting he first heard the yodel in 2014 at Montreaux, Switzerland. "I was left wondering if Kim was actually from the Swiss Alps."