Sarah Vaughan, a singer who brought an operatic splendor to her performances of popular standards and jazz, died of lung cancer on Tuesday at her home in the Los Angeles suburb of Hidden Hills. She was 66 years old. 

In a career that spanned nearly 50 years, Miss Vaughan influenced countless other singers - including Phoebe Snow, Anita Baker, Sade and Rickie Lee Jones - and made hits of such songs as ''It's Magic,'' ''Make Yourself Comfortable'' and ''Broken-Hearted Melody.'' Her ornate renditions of ''Misty'' and ''Send In the Clowns'' were invariable show-stoppers at jazz festivals in recent years, including the JVC Jazz Festival in New York, at which she appeared almost yearly.
 
Her voice remained remarkably unravaged by time; in her mid-60's, a period when most singers' vocal powers have sharply diminished, she was still close to her peak. Though her speaking voice deepened and darkened in later years, her singing retained a youthful suppleness and remarkably luscious timbre, and she could still project delicate but ringingly high coloratura passages. 

Where more idiosyncratic jazz artists like Billie Holiday excelled at interpretation, Miss Vaughan was a contralto who gloried in displaying the distinctive instrumental qualities of a voice that had a comfortable three-octave range and was marked by a voluptuous, heavy vibrato. Known for her dazzling vocal leaps and swoops, she was equally adept at be-bop improvisation and singing theater songs with a symphony orchestra. Among the singers of her generation, only Ella Fitzgerald enjoyed comparable stature. 

''She had the single best vocal instrument of any singer working in the popular field,'' the singer Mel Torme said yesterday. ''So much so that I used to call her the diva. At one point, I asked her why she had never opted for an operatic career. She got kind of huffy, and said, 'Do you mean jazz isn't legit?' She was very defensive about being a jazz singer. Where someone like Benny Goodman was able to split his musical image and record Mozart concerts, she wanted to perform precisely where she was.'' 

Appropriate Nicknames 

Throughout her career, Miss Vaughan was affectionately known as Sassy or the Divine Sarah. The first nickname reflected her sense of humor and the mischievous sexiness that often inflected her singing and stage patter. The second, appropriated from the legendary actress Sarah Bernhardt, acknowledged her phenomenonally versatile voice. Foremost among the singers Miss Vaughan admired was the soprano Leontyne Price, to whom she bore more than a passing vocal resemblance. 

John S. Wilson, in a New York Times review of a Vaughan performance in 1957, credited the singer with ''what may well be the finest voice ever applied to jazz.'' 

When Miss Vaughan appeared at Avery Fisher Hall in 1974 as part of the Newport Jazz Festival, Mr. Wilson commented on the ''soaring highs and incredibly full lows'' she displayed in her opening numbers and summed up the conclusion of her concert as ''totally virtuosic.'' 

Sarah Lois Vaughan was born in Newark, on March 27, 1924. Her father was a carpenter and amateur guitarist and her mother a laundress and church vocalist. She studied the piano from the age of 7 and later took up the organ, and at age 12 she became the organist at Mount Zion Baptist Church in Newark, where she was also a soloist in the choir. 

Career Began on a Dare 

She also enjoyed performing popular tunes at parties, and when friends urged her to enter an amateur contest at the Apollo Theater in New York, she took the dare and won first prize in October 1942, singing ''Body and Soul.'' The singer Billy Eckstine heard her perform, and six months after winning the contest she was hired at his recommendation as a second pianist and singer with Earl (Fatha) Hines's big band, in which Mr. Eckstine was a vocalist and Dizzy Gillespie and Charlie Parker were instrumentalists. 

The following year, when Mr. Eckstine formed his own band - which featured Mr. Parker, Mr. Gillespie, Art Blakey and Miles Davis, among other jazz greats - Miss Vaughan went along, and remained with him for a year. After a two-month stint in John Kirby's jazz group in the winter of 1945-46, she began a solo career. Her early solo recordings - on which she performed songs like ''Lover Man'' in full-blown be-bop style, accompanied by Mr. Parker and Mr. Gillespie -helped establish her reputation as a jazz singer. 

First Husband Was Her Manager 

During an extended engagement at Cafe Society Downtown in New York City, Miss Vaughan met George Treadwell, a trumpet player, whom she married. He became her manager, and under his guidance she made the transition from jazz cult figure to popular singing star. 

She had her first hit in late 1947 with ''Tenderly,'' for the small Musicraft label. The following year, her version of ''It's Magic,'' a song from the movie ''Romance on the High Seas,'' established her as a full-fledged pop star. In 1949, she signed a five-year contract with Columbia Records, where she remained until 1954, recording mostly popular songs backed by studio orchestras. Out of more than a dozen hits she had on Columbia, the most successful was ''These Things I Offer You,'' in 1951. Although most of her Columbia hits were disposable pop confections, she also recorded many lasting standards. Columbia recently reissued a collection of 28 songs she recorded between 1949 and 1953. 

When Miss Vaughan moved to the Mercury label in 1954, she was given the freedom to pursue a dual career as both a popular and jazz singer. For EmArcy, Mercury's jazz subsidiary, she recorded with Clifford Brown, Cannonball Adderley and members of Count Basie's Orchestra, among other jazz artists. On the parent label, she also scored a steady succession of hits for the rest of the decade. 

Songs of Seduction 

Two of her biggest successes, ''Make Yourself Comfortable'' (1954) and ''Whatever Lola Wants'' (1955), from the Broadway musical ''Damn Yankees,'' were songs of seduction in which her almost overripe timbre gave an extra edge of sensuality to come-hither messages. Her two other biggest hits were the title song of the Broadway show ''Mr. Wonderful'' (1956) and ''Broken-Hearted Melody'' (1959), a ballad with a light rock-and-roll beat. Her complete output for Mercury -263 cuts - was recently reissued. 

After 1959, Miss Vaughan would never have any commercially significant pop hits. But over the next 30 years, her reputation as consummate vocal artist soared steadily, thanks to her appearances in nightclubs, at jazz festivals and increasingly with symphony orchestras in the United States and abroad. 

During the 1960's, she recorded briefly with Roulette, then again with Mercury and Columbia, and in the 70's and early 80's she made albums for Mainstream and Pablo. It was for Pablo, run by the jazz producer Norman Granz, that she recorded the most critically acclaimed album of her career, ''How Long Has This Been Going On?'' in which she sang with a group that included Oscar Peterson, Joe Pass, Louie Bellson and Ray Brown. 

The singer's later recordings ranged from an album of Beatles tunes to a collection of Brazilian pop songs. On CBS's classical crossover recording of ''South Pacific,'' she sang the role of Bloody Mary, and on Quincy Jones's all-star pop-jazz album, ''Back on the Block,'' she and Ella Fitzgerald sang together on a version of Josef Zawinul's ''Birdland.'' In 1982 she won a Grammy for best jazz vocal performance, for her ''Gershwin Live!'' recording on CBS. 

Two Perennial Offerings 

Though Miss Vaughan's repertory during her 1980's appearances at the JVC Festival varied from year to year, two songs she would always perform were ''Misty,'' which she had first recorded in 1957 with Mr. Jones, and ''Send In the Clowns,'' which became her musical signature during the last decade of her life. 

Living up to her Sassy sobriquet, the singer liked to perform ''Misty'' as a duet with herself, singing the first half in her regular voice, than dipping to the bottom of her contralto to do an amusing imitation of a seductive male lounge singer. ''Send In the Clowns,'' the song that usually closed her shows, became her ultimate vocal showpiece, a three-octave tour de force of semi-improvisational pyrotechnics in which the jazz, pop and operatic sides of her musical personality came together and found complete expression. The performances invariably won standing ovations. 

Mr. Jones, who first worked with Miss Vaughan in Paris in 1957 when they recorded the original vocal rendition of ''Misty,'' had recently signed her to record a Brazilian fusion album on his label, Qwest. ''Sarah was the most musical singer America has ever known,'' Mr. Jones said yesterday. 

Miss Vaughan's marriage to Mr. Treadwell ended in divorce, as did her marriages to Clyde Atkins, a professional football player; Marshall Fisher, a Las Vegas restaurateur, and Waymon Reed, a trumpet player. 

She is survived by her mother, Ada, and a daughter, Deborah Vaughan, who uses the first name Paris for her acting career. Both live in Los Angeles. 

Miss Vaughan's body will be flown to Newark for a funeral service on Saturday at Mount Zion Baptist Church. 


SOME RECORDINGS BY SARAH VAUGHAN:

The Complete Sarah Vaughan on Mercury, Vol. 1: Great Jazz Years, 1954-56; (Mercury 826320; all three formats) 

The Divine Sarah Vaughan: The Columbia Years, 1949-53; (Columbia 44165; all three formats) 

The Duke Ellington Songbook, Vols. 1 and 2; (Pablo 2312-111 and 116; all three formats) 

Gershwin Live; (Columbia 37277; all three formats) 

How Long Has This Been Going On?; (Pablo 2310-821; all three formats) 

Irving Berlin Songbook; With Billy Eckstine (Verve 822526, all three formats) 

Sassy Swings the Tivoli; 1963 concerts in Copenhagen (EmArcy 832788, CD) 

Send In the Clowns; (Pablo 2312-130; LP and cassette) 

Photos: Sarah Vaughan (Steve J. Sherman, 1989) (pg. A1); Sarah Vaughan at a recording session in the 1950's. (Photo Files) (pg. B14)