Amazing grace. Today, gospel glitters. The music of churchgoers now soars to the sound of synthesizers. But the message is always `Precious Lord'

If anyone asks you who I am, just tell 'em I'm the child of God.

RHONA BENNETT belts out the gospel song with every fiber of her skinny being, while behind her a chorus 70-strong beats out the rhythm and echoes the lines. Rhona paces the stage. She pulls the crowd into her fervor. And she handles the mike like a pro. But she's not a pro. Rhona is 11 years old. She is a member of the Soul Children of Chicago, an interdenominational gospel choir made up of young people from ages 7 to 18, and directed by volunteer Walter Whitman.

The Soul Children were among 20 some groups and stars at the city's third annual Gospel Festival, spreading the ``good news'' via song. For two days - 20 hours in all - gospel music boomed out over Chicago's Loop and lake to rattle heaven's rafters.

And more than 50,000 people of all ages congregated in downtown Grant Park to hear glory shine and the devil take his drubbing.

It was a black audience salted with a few white faces. An audience where fathers, as well as mothers, cradled sleeping children. An audience partial to picnics of chicken and ribs, Popsicles and pop, not pot and booze. And it was a controlled audience. But it moved. Palms smacked, bodies rocked, arms waved, and hips swayed when music and message touched the heartbeat.

GOSPEL music doesn't carry the simplicity of sackcloth anymore. Gone are the days of its confinement to churches, tents, and convention halls, where choirs sang laments and praise to time-worn pianos, while individuals improvised as the spirit of the Lord gripped them. There's still that, sometimes, in some places - the traditional, the nostalgic. But today's contemporary gospel has rolled beyond the pews, onto tapes, platters, and discs. Its strains are heard in concerts and bars, in homes, and on joggers' headphones.

Gospel now glitters. Its sounds are laced with the complexity of instrumentation blared by electric guitars, multiple percussion, synthesizers, the whole works. And it's as stylized as high fashion from a couturier's salon. But even if the sound seems off-the-wall wild, the lyrics aren't lewd. This music carries a gospel or moral message - always.

But black gospel shouldn't be confused with contemporary Christian pop and rock, according to Anthony Heilbut, an authority on black gospel and author of ``The Gospel Sound.''

``The contemporary Christian variety is without stylistic identity, totally amorphous,'' he contends, explaining that it can be anything - punk rock, heavy metal - with religious lyrics added.

``Contemporary black gospel is rooted in traditional black gospel,'' retaining many of its characteristics, including ``moans, slurs, growls, vocal techniques, and traditional repertoire - albeit rearranged for modern listeners,'' he says.

``The cavalier way in which the term `gospel' is used by the [recording] industry is invariably at the expense of black gospel artists.''

Last weekend's festival was basically a black experience, showcasing a pastiche of gospel from ``then'' and ``now.'' And the crowd loved it all.

The afternoon sun was mean, pounding down until sweat mingled with emotional tears. And as the roster of gospel's notables was read by an emcee, one of its royalty was spotted in the audience: Albertina Walker. With the spontaneity of old-time gospel, she was pulled to the stage by applause and pleas. And there she pleased with her rich contralto voice. She's one of Chicago's own; and, like many other gospel singers, Walker got her start early in a local Baptist choir.

In the front row, strumming daintly with index finger, sat another queen of gospel music who is claimed by Chicago: 91-year-old Sallie Martin. She remembers well those early days back in the '30s, when she was professionally teamed with Thomas A. Dorsey (``Georgia Tom'' of blues fame).

Dorsey, frequently labeled ``the father of gospel,'' is credited with infusing blues and jazz into spirituals and hymns to create black gospel. He composed more than 400 gospel songs, his most famous being ``Precious Lord.'' And during the cruel days of the Great Depression, he and Martin livened up black churches with their gospel music, promising good to the poorest of the downtrodden. Originally from Georgia, Dorsey and Martin adopted Chicago years ago, and both still live here.

Listening to the array of entertainment, Martin nods approval to the contemporizing of gospel. But she has definite ideas as to where gospel should be sung. She's not in favor of the nightclub circuit.

``That's the same as feedin' the children's bread to dogs; they're [nightclub patrons] not thinkin' about the Word. They're thinkin' about another drink.'' There's a better atmosphere for receiving the Word,'' says this regal songstress, whose business acumen led her to found a publishing company to produce gospel sheet music.

``I sing now like I did then. If the spirit comes, it moves me. If I feel nothin', I move nothin','' says Martin, warning modern gospel singers to be ``moved'' by the spirit, not cash.

CLEARLY, gospel music is big business today. Figures inside and outside the recording industry put gospel at somewhere between 4 percent and 7 percent of the 4.4 billion recording sales nationwide in 1985, while classical tallied 5 percent and jazz, 3 percent. That figure is up from the early '70s, when gospel was generally lumped in the musical category of ``All others.''

The upsurge in sales comes largely from ``crossovers.'' That's when gospel singers remain gospel singers, cutting their albums for the gospel market, but - if fortune smiles - their recordings cross over into the musical mainstream, because white youth often find their music wholly danceable, despite the holy lyrics. This phenomenon burst forth in 1969, when teen-ager Edwin Hawkins and choir members recorded some songs to raise funds for their church. Their album included a Baptist hymn, ``Oh Happy Day,'' which was picked up by an underground rock station to become a crossover hit.

But crossover coups can bring criticism to a gospel singer's doorstep from the more conservative church elements. Nobody knows this better than three festival performers, Tramaine Hawkins, the Winans, and Jessy Dixon.

Unfortunately, midway through Dixon's performance on the festival's final night, the clouds ripped open, unleashing a downpour. Thousands fled. Scores stayed. An hour later, when the rain slackened to showers, the thousands streamed back to their seats. Umbrellas went up, bobbing to the beat. And the concert went on.

It takes more than a Noah-style deluge to halt a hallelujah weekend in Chicago. Amen.