Sarah Vaughan has been "The Divine One" for 30 years now, a for-once accurate moniker that has stuck since television personality Dave Garroway gave it to her in the '50s. "He was a disc jockey in Chicago then and used to play my records constantly," she recalls.

"I was working a club there, making $250 a week. By him doing so much talking on the radio about me, I went to $750 a week and bought my first Cadillac Sedanette, the little slanty thing. That was the first one! RII--IICH!" The laugh is hearty, the Cadillac still shiny new in her memory.

Vaughan's other nickname, the one she is better known by in the community of musicians, is "Sassy," bestowed even longer ago by Washington pianist John Malachi. "He doesn't remember doing it but I do," she laughs. "I was such a fresh kid."

Sassy she may be, but Vaughan wears her laurels shyly, like the beauty queen who can't quite believe grace and talent can be so warmly rewarded. She's proud of her wall full of awards, and of praise such as that from composer-conductor Gunther Schuller, who has called Vaughan "the most creative vocal artist of our time."

But you always feel that, really, Sarah Vaughan would rather be singing.

Like the best in any creative field, Vaughan's invention is intuitive, her art instinctive. She is least comfortable with talking, most comfortable with doing. Or the shoo-be-do-be-doing.

"I don't know," Vaughan insists quietly when asked about her distinctive approach--some call it assimilation--to song. She is not being disingenuous, but her gift for inspired and complex improvisation apparently does not extend to casual conversation, where she often seems as introverted as she is extroverted on stage. "I just . . . get out there and sing. I don't think about it, I just get out there and do it."

On a sweltering Washington afternoon, however, Vaughan is steadfastly refusing to go "out there." Instead, she is maintaining her cool in the ice-bucket air-conditioned hotel suite she's occupying during her week-long residency at Charlie's Georgetown; a rare nightclub showcase, it was sold out before she sang a single note.

In the suite, the curtains are drawn hermetically tight: light means heat. Vaughan's road manager, shivering playfully, sneaks behind the curtain and basks in a quick shot of sun, but Vaughan looks utterly comfortable on her couch.

There are times away from the spotlight when Vaughan seems genuinely surprised to be in the music business, much less a member of its royalty. She neither dreamed nor trained for such a career, though she was always interested in music itself. As a child, she'd been just another voice in Newark's Mt. Zion Baptist Choir. She never took voice lessons--still hasn't--though she did spend eight years studying piano and organ starting at age 7 ("at 50 cents a week!").

When she was 14, Vaughan "used to sneak up to a nightclub, the Alcazar in Newark, and listen to trumpeter Jabbo Smith play. I was underage, but they used to let me sing a number; used to get pretty nice little hands, too. But there was a girl blues singer in there, and she told the boss if I didn't get out of there, she'd call the ABC board."

It would be four years before she stepped out publicly again. In 1943, when the 18-year-old Vaughan entered an amateur contest at Harlem's fabled Apollo Theatre, a career as a hairdresser seemed a stronger possibility. After all, she points out, "you didn't get more than one chance at the Apollo."

One chance was all Vaughan needed, however, and she walked off the stage with a first place. At the time, all it meant was $10 and a week's engagement at the Apollo. During that week, Billy Eckstine, the velvet-voiced crooner who was then with the Earl Hines band, heard her and convinced Hines to hire her. And so, two weeks after entering an amateur contest, Vaughan found herself working as a professional. Time has made her consummately so.

Vaughan spent a year with Hines (as vocalist and second pianist) before joining up with Eckstine's pioneering be-bop band, the one that included Charlie Parker and Dizzy Gillespie; her vocal acrobatics, subtle harmonic variations and fervid imagination were perfect for such fast company. Vaughan has always been widely admired among musicians for her facile phrasing, rich contralto and the startling control and fluency on both ends of her range. Her vocals were once described as "bituminous" because of her ability to dig down deep into both melody and lyric and bring out rich and engaging sounds. That quality anticipated the Bell Telephone Co. commercial she did in 1980: "Reach out, reach out and touch someone." That's something Sarah Vaughan has been doing since 1943.

By 1945, Vaughan had settled into an increasingly successful solo career, working most often with a trio, though she has worked with everything from big bands to symphony orchestras (including the National Symphony on several occasions). She was perhaps most popular during the '50s and early '60s, when her records and personal appearances elevated Vaughan to that select circle of international pop divas (Ella Fitzgerald, the other great American singer in that group, had also gotten her start winning an Apollo amateur contest).

Like many singers who straddle the line between jazz and pop singing, Vaughan is badly represented on vinyl. It's an area she prefers not to talk about. Twice, she has gone long periods (six years once, four years another time) sitting out contracts and refusing to record; too often she has been forced to record commercial material not suited to her supple and expressive voice.

At 59, Sarah Vaughan is working as hard as she ever has during her 42 years in the business. Clubs, concerts, recordings--they keep piling up and the passage of time only substantiates all the praise.. Vaughan's voice is still a marvel, her instincts diamond sharp. And her coterie of fans continues to expand.

"I think most of my fans were raised up with me," she says. "They were young when I was young and now we're just a little older . . ."--she laughs--"and they're still there. Plus I'm getting a young crowd, 'cause my old records are still coming out, so it ain't that bad." In fact, she adds, "It's marvelous."

"You figure around this age the usual trend is for things to start petering out. Well, it's petering up for me!"