Ask any of the Roberta Martin Singers a question, almost any question. When called upon to answer, these gospel pioneers, veterans of 30 years of spreading The Message through song, always respond in a spiritual key.

Ask how difficult it is, after a 15-year retirement, to evoke the same smooth, close harmonies which first brought the group fame in 1936.

"Once God brings us together, that's all it takes," answers Rev. Archie Dennis Jr., looking out over the Smithsonian's Baird Auditorium where he and the eight other Roberta Martin Singers have been reunited. In connection with Black History Month, they will appear in a weekend of concerts and workshops beginning tonight. Dennis is a full-bodied baritone from Pittsburgh, Pa., but his reply is a soft, heavenly whisper. "It's like riding a bicycle, you never forget."

What turned a few teen-agers fresh out of Sunday school into inernational concert and recording artists? "It's a gift," says Eugene Smith, " a gift from God that evolved with experience." Smith takes his own good time with the answer. The long nod of his head is as grand as his slow, deliberate, Baptist-preacher's enunciation: "No professional training what-so-ever." Smith is an original member of the group. Roberta Martin asked his mother if he could join in 1934 when Smith was 12 years old.

Delois Barrett Campbell throws back one of many long, black, ringlet curls. She is a lyric soprano who joined the group as a teen-ager in 1945 and became one of the first gospel singers to employ operatic techniques. Her vocal training? God just gave it to me for free," laughs Dennis.

"In the '20s and '30s, people equated gospel with blues and jazz. They were used to hymns but nothing with a beat until we started adding one," Smith explains, adding that church-going people once considered jazz and blues the devil's music. "Yeah, it was the beat that got 'em," adds Campbell.

Inspired by the later Roberta Marting, a singer, pianist, composer and arranger, the group invented techniques that are the basis for many recent gospel and pop styles.

One of Martin's main innovations was her use of the piano as a primary instrument, as important as the vocals.

"You hear those runs and chords?" Dennis asks during a rehearsal. Richard Smallwood, a local pianist, is running his right hand up and down the keys while the left hand bangs out the melody of "Rock My Soul (In The Bosom of Abraham)." "That's the Roberta Martin sound."

Smith developed the style of narrative introduction that is now a standard in gospel music. As the piano welled up in the background, Smith would arrange the lyrics of the upcoming song into an inspirational anedcote: "If you're sick in your body, don't know where to turn, I know someone who's a body fixer and a burden bearer. Why don't you try Him," Smith says, rehearsing the message. The chorus follows him in with "Won't You Try Jesus."

At the height of their popularity in the 1940s, the Roberta Martin Singers perfomed at Madison Square Garden, Carnegie Hall, Chicago's Eric Crown Theatre, the New York Coliseum, and in 1967 at Ital's Spoleto Festival of Two Worlds, traditionally limited to classical musicians. In the beginning what we did were not so much concerts as revivals. And if it wasn't a revival we were singing at, it was just called a 'program.'" says Smith. "But after our music got in greater demand, we started singing 'concerts' too."

"Back then there were no recordings to procede you," Dennis says, reminding Smith that it took weeks and weeks on the road -- performing at large and small churches throughout the country -- to generate that demand.

"On Sunday mornings you had to make the rounds. Three or four churches a morning," Smith says. "And because we were black, we traveled by car. And the church people housed and fed us. Couldn't stay in hotels back then."

By 1945, the group reportedly was earning more than $3,000 a week.

Since then, gospel music has become a mutimillion-dollar industry, and many of the contemporary singers in that boom got their lessons from Roberta Martin firsthand: The late, legendary jazz singer Dinah Washington and popular gospel recording artist James Cleveland started their careers as Martin Singers. "We paved the way and they went in," Smith says, again in his pulpit style, referring to Washington, Cleveland and musicians just coming on the gospel scene such as Andre Crouch and Edwin Hawkins.

Mahalia Jackson, too, sand the gospel to the tune of millions. "We were never exposed," Smith says. "Mahalia, she broke into the white market. We don't resent it. We like to see people getting as much as they can." Why was Jackson able to do it?The answer this time is surprisingly void of divine intervention. "Through luck," Smith says. "By being at the right place at the right time." There is a chorus of agreement. Sometimes, the Lord works in mysterious ways.

"The new gospel sound has its place," Smith says. "Time has just moved on and there are a whole lot of people who like it. I wouldn't want to be a part of it, though. Because you see, I am, as they say, old and settled."