A Gift From Ella Fitzgerald to Tin Pan Alley : Jazz: The singer’s ‘Song Books’ pays tribute to the Gershwins, Ellington, Porter, Rodgers & Hart, Berlin and Arlen, Kern and Mercer.

On Tuesday, another milestone will be reached in one of the music world’s longest running careers. Verve Records will release “The Complete Ella Fitzgerald Song Books,” comprising her entire 1956-64 series of tributes to great American songwriters, combined into a 16-CD set, complete with booklet, essays and lavish illustrations.

This will be a logical step in a career that took its most portentous move when Fitzgerald first stepped nervously into a recording studio. It was June of 1935; she had just turned 17, and was the vocalist with the Chick Webb band.

She taped her final session in 1991, ending a virtually continuous career that remains unmatched in longevity by any artist in the history of recording.

Longevity is not the name of the Fitzgerald game: What mattered most is consistency of achievement. Along the way she has influenced thousands of vocalists. Her impact did not just grow slowly over the years; it was there from the start, affecting her contemporaries.

Anita O’Day, just a year her junior, recalls hearing “You Showed Me the Way,” a tune Fitzgerald wrote and recorded in 1938, then going to hear her sing with the Webb band at the Savoy Ballroom in Harlem just after she had recorded her first hit, “A Tisket a Tasket.” “I followed her for a long, long time,” O’Day says. “In fact, Ella is still my girl.”

Natalie Cole, many years her junior, met her when she was 6 years old.

“She was my first vocal inspiration. I didn’t know then that it was ‘jazz’--I only knew that it was great. Her voice was like honey.”

Now retired and living in Beverly Hills, Fitzgerald remains very much among us via frequent reissues of her recordings. The statistics of the “Song Books” set are staggering: They include three CDs each for the Gershwins and for Duke Ellington; two each for Cole Porter, Rodgers & Hart, Irving Berlin and Harold Arlen; one for Jerome Kern and one for Johnny Mercer. (Suggested retail price is $250; there is no cassette version.)

“These are absolute landmark records,” says Mel Torme, one of her most loyal followers. “In 1938, I bought her record of ‘F.D.R. Jones’ with Chick Webb; I was 13. . . . My ‘Ella Be Good’ routine is taken note-for-note from her scat version.”

The concept of making definitive versions of classic popular songs was due to the initiative of impresario Norman Granz. Featuring her on his “Jazz at the Philharmonic Concerts,” Granz became her manager in 1954, but could not record her for his own label; she was under contract to Decca, where she was still alternating good songs with such monuments to mediocrity as “Somebody Bad Stole de Wedding Bell.”

Granz knew that a touch of class was needed in her work; soon after he wrested her from Decca and launched her on his new Verve label, the period of work that was to make up “Song Book” was under way.

All the elements that brought potential permanence to the songs enabled Fitzgerald to etch them in history. Aided by the arrangements of Buddy Bregman, Paul Weston, Nelson Riddle and others (the Duke himself leads his band on the Ellington sets), she brings the right sensibility to each work, be it gentle romance (“With a Song in My Heart,” “Why Was I Born?”), wit and irony (“Something’s Gotta Give,” “Ace in the Hole”), spontaneity (on several of the Ellingtons) or sophistication (often in the Cole Porters).

Though her range broadened and her timbre took on added purity, there were no drastic changes over the decades. If there has been one flaw attributed to her, it was expressed by Bregman: “She sings magnificently, but gives her all to the music rather than the words.”

There is a small measure of truth here, though in many songs the lyrics and music are deftly enough interwoven to defy any singer to misinterpret them. If Porter presents a problem in the verse of “The Lady Is a Tramp” by requiring “sad” to rhyme with “Noel Coward,” the fault is not Fitzgerald’s. The substitution of “Have You Met Sir Jones” for “Have You Met Miss Jones” sounds clumsy; it would have been better to omit the song.

What the “Song Books” offers, along with the generally estimable quality of the material (and the inclusion of a surprising number of verses, some of them quite obscure), is the quintessence of Fitzgerald: the flawless diction, the purity of intonation, and perhaps most of all the sheer joy of vocal expression.

In the 1990s, Fitzgerald remains what she was in the 1930s: the singer to whom others look for guidance. Typically, one of today’s hottest young jazz artists, Nnenna Freelon, says: “Whenever I want to learn a new tune, if Ella has recorded it, I always turn to her. The effortlessness, the clarity, the beauty of the instrument--she gets you right in the heart.”

Singers and songwriters alike agree that “Song Books” accomplishes what it set out to do--bring together about 240 tunes representing Tin Pan Alley’s golden era, interpreted by someone who had respect for the melodies but felt free to indulge in slight variations.