AUSTIN, Texas (AP) -- With their red, white and blue tutus and Taylor Swift t-shirts, Rachel Emling and Mikala Crews were everything Formula One wanted at the US Grand Prix: young fans who would travel across the country for a mix of pop stars and fast cars.

Tens of thousands packed into the Circuit of the Americas on Saturday night for Swift's only concert of the year at Formula One’s only race on American soil.

Formula One's goal in booking Swift was to hook a new generation of fans to their sport in America, long considered an untapped market for the global racing series. Landing fans like Emling and Crews, NASCAR fans from Jacksonville, Florida, was exactly what they hoped for. They came for the concert and love the cars.

“We’ve been watching a little bit. It's cool,” said 20-year-old Emling, who said they’ll return for Sunday's race. “We like racing.”

“It’s different. There are so many people here for the race. It's a good mix,” Crews said.

The race weekend scheduled her show after Saturday qualifying and before Sunday’s race. One group that will be watching is Liberty Media, the American group that is taking over Formula One's commercial entity and will be looking for ways to grow the sport. Track president Bobby Epstein had predicted as many as 40,000 would be lured in by Swift.

The weekend is a big opportunity for the singer as well. Race officials hope the entire weekend will draw about 250,000 people with Swift rumored to soon release a new album. And she’s not alone in the music lineup. Usher and The Roots were scheduled to play at the track after the race Sunday night.

But Saturday night belonged to Swift. 
 
After Saturday's qualifying ended, young girls with their parents and packs of young women started filing into the stadium. They stood in line at food and drink vendors alongside the die-hard race fans dusty from sitting all day in the grass berms around the track.

Charlene Frollo of Austin brought her daughter in a gaggle of girls, all aged 9 or younger. As a group, they wore pink and white “Swiftie” shirts Frollo had designed herself. They arrived well after the day’s main event on the racetrack but still got to see some of the support races and hear the cars growling around the circuit.

“It was fast. It was like ‘RRRRRRRR,’” said 8-year-old Brie Bauman.

Would they like to see more?

“Yeah, I guess so,” said 7-year-old Avery Frollo.

Charlene Frollo said her husband and sons will be coming back for the Sunday race, but was glad the girls got to experience something new.

“We had a second to show them the cars. Now they know about Formula One cars and they know now this is the only track in the United States, which is kind of big deal so close in our backyard. It’s wonderful for them to come here for the concert and see the bigger world out there,” Charlene Frollo said.

Don Burger, a Formula One fan from San Antonio, brought his 22-year-old daughter who wanted to see Taylor Swift. She's not a racing fan but he sees a twinkle of interest after getting her out to the track.

“She’s stands it when I put it on TV at home,” Burger said. “I think she's a little more interested than she was before. She flipped through the program. She told me the other day, ‘I’m actually looking forward to the racing, too.’”

As for the Formula One drivers, some would like to see Swift. Others plan to skip the show the night before they race.

“I'm going to try to. I know Taylor a little bit. She’s amazing. I'm a massive fan of hers,” said Mercedes driver Lewis Hamilton, the two-time defending Formula One champion.

Not Romain Grosjean. The Haas F1 driver planned to get away from the track.

“I like to have a very quiet dinner and a glass of red wine. I’m French,” Grosjean said.