Inside a small sanctuary at a South Los Angeles church, about 40 youngsters break into a sweat during an energetic rehearsal of gospel tunes that have them lifting their arms and stomping their feet.
But choir director Antwon Martin tells the teenagers to put away the makeshift paper fans they have assembled to cool themselves.
"It's going to be 10 times hotter on that stage, so you better get used to it," he says.
That stage is at the Shrine Auditorium, where the choir -- made up mostly of Lynwood High School students -- will be competing as one of two youth division finalists tonight in the annual Gospelfest, which chooses the best amateur gospel talent in Southern California.
A collection of young people of different backgrounds, neighborhoods and musical abilities, the group was formed less than a year ago but has parlayed its growing sense of kinship and fervent spirituality, through a series of preliminary sing-offs, into a spot in the final round.
The ensemble calls itself the Chosen Generation. Rather than aimlessly hanging on the corner or in the mall after school, rather than endlessly spinning numbers from the latest rap disc, the singers have chosen to devote much of their spare time to rehearsing music steeped in the traditions of the church.
"This has kept a lot of kids out of trouble," says Joseph Knight, 17, a Lynwood High senior and choir president. "It gives us something to do besides being at home. I love to sing, and this is like a second family to me now."
Knight and a couple of other students were involved in a gospel group at the school a few years ago, but it disbanded when the director left. After budget constraints precluded hiring someone else for the job, the students prevailed on Martin, a geometry teacher, to volunteer his time after class.
"I told them they had to demonstrate they were serious, and they did," says Martin, an accomplished pianist and son of a minister who began playing for his father's church in Wilmington, Del., at age 12.
He is sitting in a pew during practice at the Greater Bethel Apostolic Church, where his father, the Rev. Aaron Martin, is pastor. The group has been rehearsing about a month for the Shrine event, which is in its 19th year.
Earlier he took the sopranos, then altos and tenors, through their paces in "We Praise You, Lord," one of two numbers the group will perform tonight.
The youngsters have a dance routine worthy of the Temptations, lifting their arms rhythmically to each beat, swaying from side to side and pounding their feet to punctuate phrases like "We praise you and lift you up."
"Every step should be firm; put some energy behind what you're doing and let me hear you," shouts Martin.
The singers will have eight minutes on stage, and Martin tells them to make the most of it.
With drum and guitar accompaniment, the group finally produces a sound that bursts through the church doors and skips half a block down the street. At the end of rehearsal, members hold hands in a circle, praying to stay together and keep working like a family.
Martin says he has witnessed a metamorphosis among many of his charges, as youths full of self-doubt produced by hard lives have grown into self-confident young adults. Their grades have risen, and there is real sincerity in the words of praise they sing. "They are looked up to as representing their community, their family, their Lord -- everything that is positive," he says.
Tiffany Cunningham, 16, says being in the choir has opened her to a new world. "It has brought me out of my shyness," she says. "Before, I wanted to stand behind people and hide, but now I can be out front."
DeAnthony Friday, 16, says that, even during the days of the old choir, he always admired the singers and wanted to join their company. When the new choir formed last December, he jumped at the chance.
"It's not only helped me to sing better but encouraged me to be more in church and live the right life, basically," he says.
Despite its relatively short existence and lack of experience, the Chosen Generation has developed into an accomplished ensemble and been invited to sing at conferences and other events from Sacramento to San Diego. The singers have invited other young people from the surrounding community to join them. One is Vanessa Dorn, 19, who graduated from Compton High and is training to become a licensed vocational nurse.
"What I see is a lot of young people who have a lot of energy, who are really motivated and are not doing this just to be doing something. They have a purpose," says Dorn, who joined the choir in July.
So much so that they sometimes have to be urged to go home, says Lynwood High Principal Jose Urias.
"They practice at the performing art center at school and sometimes we have to send security over to make sure the kids go home and do the other things they have to do," he says. "They're great kids and that shows in what Mr. Martin has been able to do with them. They have grown under his leadership and commitment."
Urias says the school will be out in force at the Shrine, cheering on the choir. The other competitor in the youth division is the First AME Church Pasadena Youth/Young Adult Choir.
Proceeds from the event this year will benefit the Ronald McDonald House charities and the African American Future Achievers Scholarship program for high school seniors.
Members of the Chosen Generation say they are nervous about their appearance before 4,000 people, but confident.
"We're absolutely looking forward to it," Dorn says. "But to know we made it this far is a blessing."
Tickets for Gospelfest, at 7:30 p.m. tonight, are available at the Shrine Auditorium, 665 W. Jefferson Blvd., Los Angeles, and through Ticketmaster, (213) 480-3232. Prices range from $25 to $35.