MOSES LAKE — “Stop dancing like you’re apologizing for being here!” shouts Rian Miles, shortly before she’s drowned out by the opening lines of Rihanna’s “Only Girl.”

At one end of a studio at the Ballet Academy of Moses Lake, Miles’ jazz dance students bunch up and form three lines.

Three by three, students watch themselves in a mirror spanning the length of the studio as they practice their techniques, watching to make sure their arms cut straight lines through the air as they turn on the balls of their feet, or that their legs come far enough up into the air as they leap.

As they bounce, jump and chassé across the floor, Miles runs between them, straightening their arms, lifting their legs and shouting out advice, all while avoiding being bowled over by the young women as they hurtle sidelong.

And, as Miles hammers into them — laughing, smiling, playing, but hammering nonetheless — they’re watching themselves not just to see their limbs reach the appropriate height or form clean lines, but that they do so with grace, strength and confidence.

For Miles, who also teaches hip-hop, tap and lyrical dance styles, Wednesday nights at this time are high-level jazz technique classes, focusing on improving the fundamentals of the most advanced students.

The classes start with cardio exercises, which Miles manages to do alongside the students with an extra shimmy or head bob whenever she’s feeling the music, her jet black hair shaking back and forth freely.

In these technique classes, students practice individual components of the dance style, such as a soutenu or ball step. On other days, the students attend rehearsal classes, which take those elements like puzzle pieces and build them into a coherent whole.

“Smile on your face, open your heart,” Miles bellows. “You’ve got to open that chest up and take it in!”

Just across the wall and feet away, Lacy Stowers, dressed in all black like a secret agent, blond hair in a tight bun, walks around the neighboring studio, sizing up her troupe as they hold a pose.

“It comes from the back, all the way out through the shoulders and the arms, and you have to hold it,” Stowers says. “You can’t relax, because that’s when it starts to look sloppy, OK?”

Ballet is particularly well known for being an intense, rigorous art form, full of hard angles and straight lines, and Stowers walks the students through each muscle group along their backs, telling them to push forward through their pelvis to straighten their spine.

But, while Stowers’ classes are certainly regimented, that’s not to say that she doesn’t ever relax or act friendly with her students, chuckling with them as they work through the splits or a tough technique.

“Don’t arch your back, or it looks like you have a big ol’ booty,” she warns, making a serious comment about posture, but still expecting the giggles her comment elicited from her students.

Stowers purchased the Ballet Academy of Moses Lake in 2007, and though the business had been open for almost a full decade prior, there was a lot of work to be done rebuilding a depleted pool of students. For the first six years, Stowers was the only full-time teacher, and, true to its name, the academy only taught ballet.

But then, shortly after the new decade began, the mother of one of Stowers’ students asked if she could invite a dancing buddy to teach a jazz class. That dancing buddy, Miles, started coming over from the west side to teach master classes over the weekends, where she and Stowers became fast friends.

Though Miles eventually left for the Big Apple, where she taught a “Ready, Set, Dance!” program for youth with the New York City Dance Alliance, it was not a permanent hiatus from Moses Lake. Around a year later, in 2013, Stowers made her a sudden, unexpected offer.

“Then I was like, ‘hey, why don’t you move to Moses Lake and come be my business partner?’” Stowers said.

Miles, who had for years sworn to all who would ask that she would never teach in her own studio, didn’t need to be asked twice. She leapt at the chance.

“It was that easy,” Stowers and Miles said in unison.

With Miles as co-owner, the academy no longer taught just ballet, though the studio’s name had by then stuck. And that diversification is more and vital as the dance world changes, Stowers said.

“Dance in general has evolved immensely just since (Miles) and I were dancing. Just being a ballerina and going to a ballet company, you can’t really do that anymore. As a ballerina, you have to know how to do jazz, you have to know how to do contemporary.”

The selection of classes didn’t simply diversify — in their own distinct way, either instructor’s classes were improved by the presence of the other.

“We can bounce ideas off of each other, like, ‘Hey, I’m really struggling teaching these girls this pirouette turn,’ and she can say, ‘Well, have you tried doing this?’” Stowers said.

“You’re working with your best friend and your sister,” Miles said, “and it’s something that we share, as far as the love of dance, so when we talk about it or have ideas, it comes from the passion we share.”

The two women also share a passion for their students, eager to push them to reach their potential, both as dancers, but also simply as young women.

“We teach them to show up on time, how to respect adults, how to treat each other,” Stowers said. “You don’t sit there and put someone down, you help one another.”

Now in their seventh year of partnership, as they’ve watched each other and their students improve, Stowers and Miles don’t see the business hitting a plateau anytime soon.

“There’s so much talent, it’s untouchable,” Miles said. “This is really our seventh year together, but it’s still such a baby. You still see growth, you still see the love.”