Ask a Rockette what it takes to dance alongside the city’s iconic holiday performers at Radio City Music Hall and she might say talent, determination, passion or unwavering persistence.

For 37-year-old Heather Langham, the road to the big stage involved six tryouts and 10 years of rejection.

“Passion fired me through it all,” Langham said, recalling the long journey that started in 1999 when she was 19 years old.

Fresh out of high school, the Manhattan resident  — who practically grew up on the ballet bar of her mother’s Arizona-based dance studio Langham School of Dance — traveled to the city to chase a dream many young dancers know well.

“I knew I wanted to be a Rockette at a fairly young age. I had been dancing since I was 2 years old and at 12 I realized it was a possibility,” she recalled. What she didn’t realize, however, was just how rough the road ahead would be.

Langham, who studied jazz, ballet and tap, went into her first audition at the Sixth Avenue theater full of hope — “dance was my life, 100 percent at the time,” she said. With a headshot in tow, she joined nearly 500 other women for a grueling two-day process, learning a basic kick, turn combo that gradually increased in complexity. In between three rounds of cuts, the dancers were taught more steps until they were working with a full Rockettes dance number, she said.

Langham made it to the final round of the second day of tryouts with only a “handful of women,” but that’s where her journey ended. Determined to head back the following year better prepared, she continued to study dance, switched her eating habits and took up weight training (to handle the 300 kicks the dancers do per show), only to be cut at the second-to-last round.

After trying her luck the following year at the Rockette Experience dance class, a two-hour intensive that includes a 45-minute mock tryout led by Radio City’s current and former dancers, she was cut once again.

“I had gone from the final round, to the second to last round, to being cut in the first,” she said, expressing her initial discouragement.

The most challenging part, she recalled, was not getting feedback from the directors as to why she hadn’t made it. Given the meticulous requirements — a Rockette must be between five-foot-six and five-foot-ten and a half inches tall — the reasons Langham got the boot initially could have varied from skill to something as simple as being an inch taller than the height mark the team was looking to fill. Langham returned to audition three more times before finally being dubbed a Rockette in 2009.

When she got the call from Radio City late August that year, her “hands and entire body were shaking and a wave of emotion came over me. I was just in tears because of everything I had gone through to get to this point. I had finally achieved my dream.”

That wasn’t the end of her audition process. Rockettes are required to try out for a spot each year, even after they’ve held the coveted title. Now nine years into her career (making the cut each year), she still humbly remembers what it was like to stand onstage for the very first time.

“What keeps me going is the dancers that aspire to be like me. The girl who dances next to me this year is a first-year and when we finished one of our shows she looked over at me and said, ‘you’re such an inspiration,’ ” Langham gushed.

The road to the Rockettes looks different for all of the team’s 80 dancers, though. Audrey Thelemann, 24, now in her seventh year as Rockette, recalled making it onto the team as a SUNY Purchase college freshman after her very first try. She, too, had prepared by attending the Rockette’s intensive class.

“That first time, I have to tell you, the nerves I felt standing in line with 500 women who have the same dream,” Thelemann, a Park Slope resident, said. “I’m very gracious [to have made it so quickly] ... There’s such a joy of being onstage with those women in that historical theater.”

Both Langham and Thelemann hope to reach their goal of being Rockettes for 10 years.

The “Christmas Spectacular” plays at Radio City Music Hall through Jan. 1.