MIAMI – Twenty years ago, when she was just 17, high school student Katie Christie formed a young people's musical theater group here to promote cultural and political harmony. 

Today the group, known as Voices United, still thrives. Its goal is still the same and Katie – now the mother of a teenage girl who's a current cast member – is still the organization's director.  More than 1,000 alumni of her troupe are scattered around the country.

"I think what you get in the program are the foundations for success for a full life," said Sal Richardson, an attorney, former Voices United cast member and vice chairman of its board of directors. "What you see immediately in kids is an increase in their confidence, an increase in their self-awareness, an increase in their self-respect and an increase in respect for others."

This year, another group of 90 children, ages six to 18, from 45 different South Florida schools worked together on weekends to write, rehearse and present their own stage production to enthusiastic audiences. Some of the students also recorded a CD of their own songs at a professional studio. For next year, there are plans to make a film. And they just launched a new Voices United Web site for the group. 

Raul Hernandez / NBC News
Katie Christie speaks with group members

Video: Troupe empowers teens on, off stage
Web-only video: Program works to give young people a 'voice'

Because Voices United is a non-profit group funded by donations and grants, raising money is always a challenge. Some of the students wanted to go to Japan to perform with children there. So they started collected pennies which attracted donors and eventually brought in $10,000, enough to finance the trip. "I love them, they're my kids," said Katie. "I really just believe this is what I'm meant to do."

Raul Hernandez / NBC News

Members of Voices United practice their dance moves.

Learning to understand herself
Voices United sprang from Katie's own upbringing and confusion over her identity, a feeling she would later discover she shared with many other young people. Of mixed-race heritage, Katie was adopted and raised in an all-white household with a Greek father and Jewish mother, whom Katie describes as unconditionally loving and always supportive of her. Still, Katie couldn't understand why her skin was darker than theirs and why she felt prejudice outside the home. "I grew up in an experience where everyone around me looked different that I did," she said.

To try to address Katie's shyness, her mother put her in theater, but it wasn't until Katie's junior year in high school that the decision really paid off. In 1989, she joined Peace Child, a multicultural traveling theater company, where she found friends.  Together, they performed in the then-Soviet Union with Latvian children. During a performance there, while she was singing in English about peace, Katie noticed that members of the audience were crying, even though they didn't understand her words.

"For the first time I really felt like my singing mattered and it was making a difference and people were feeling what I was feeling," she said. "I came home and it was right before my senior year and I was, like, I'm going to start a program like this in Miami -- and everybody thought I was crazy."

Raul Hernandez / NBC News

Two young girls practice their lines for a Voices United musical performance

A safe place for cultural and personal awareness
With its primary goal of providing cross-cultural education through the arts, Voices United found a perfect fit in multi-cultural Miami. According to the latest U.S. Census data, Miami-Dade County's 2.3 million residents are 62 percent Hispanic or Latino, 18 percent non-Latin white, and nearly 20 percent black.

As important and inspiring as the group's work is on stage, the real aim of Voices United is to address cultural issues and youthful concerns off-stage, in workshops where everyone is allowed to speak and there is lots of support.

"I think what makes it work is that I'm really listening to the kids. They really do have a place where they feel safe and they can talk about anything through any experience and they're going to be accepted at the end of the day," said Katie. "We're using the art as an excuse to deal with all these issues."

One of the techniques she uses to help teenagers deal with important matters such as drug abuse, peer pressure, discrimination and domestic abuse is called "Step Across the Line." With all the kids lined up shoulder to shoulder, facing a white line of tape in front of them, Katie will ask them to step across the line if they have been involved in a particular issue.

"Step across the line if you've ever been offered drugs," Katie called out as a handful of students then walked forward. "Look at the people on your left and your right," she said. "Step across the line if you've ever discriminated against someone."

"They step across the line and it occurs to them that now I'm taking ownership of this thing that's just been inside my head or inside my heart," Katie explained, noting that in group sessions which follow the Step Across the Line exercise she and the students then talk openly about all the issues that bother them.

"The idea is to help, really, to get everybody to understand who is going through what and it shows them that a lot of people are going through similar experiences," she said. "We talk about it and I think they're like relieved to be able to have a place to talk about those things."

Mina Saja, one of the teenage cast members, says she loves waking up on Saturdays to join the other students for Voices United rehearsals. "We're just all best friends and we feel that we can talk to each other, thanks to the program," she said. "I know for me, Katie is like a second mom.  If I need something, I can call Katie or I can Facebook Katie, or whatever.  Like I know she's always there."

Powerful art
On a recent Saturday morning at the New World School of the Arts in downtown Miami, rehearsals were in full swing for a specially selected group of performers who make up the Voices United traveling company. Over and over, they choreographed dance steps and practiced singing. Then for about a half-hour, they broke up into small groups to write new material for an upcoming performance. The goal this day was to poke fun at silly commercials on television. It was much lighter fare than some of the other topics they have tackled, including environmental issues, drunk driving and the human cost of war.

"What I want them to do is talk about all the things that are important to them, the things they notice in the world that don't sit quite right with them," said Katie. "It's not about me creating shows about what I think is important to young people. It's really about their thoughts and feelings and what they think is important in the world."

An emotionally moving scene was being rehearsed on this day was about a young girl's fears for her father who's gone off to fight in war. As a dozen actors mime a battle scene behind her, a 13-year-old girl with a beautiful voice sings the song she wrote herself, called "Dear Dad."

The singer is Maya Hunter, Katie's daughter, who wrote the lyrics and music after the death of her own father, who passed away two years ago.

"Through Voices United she was able to let her own feelings and her thoughts out through writing this song," said Katie. "I was quietly thrilled to see the process really worked for my own child."

For the past two decades, thousands of South Florida youngsters have had the same chance to be heard and supported. "When I was a young person, I didn't feel like I had a voice. I didn't feel like people were listening to my thoughts and my feelings," said Katie, who makes sure that's no longer the case for others. 

"Kids need to be listened to," she said. "They need to be valued, because they're going to inherit the world from us and they should be allowed to put in their two cents. We should be listening."

Click here for more information about Voices United.