Period.

The Ellington influence is as vast as the journey was long from the dance band podium at Harlem's Cotton Club to the concert stage at Carnegie Hall. In those 50 years, Ellington became America's most prolific composer, both in terms of the number of pieces (conservatively, 2,000, from sentimental ballads to sacred concerts) and the variety of forms he addressed (solo, small ensembles, orchestras).

Like Shakespeare, Ellington created a singular, immediately identifiable style with universal appeal. He elevated writing to previously unimagined heights of sophistication, using notes instead of words. His orchestrations were comparable to those of European classical music. Yet the music remained quintessentially American, and specifically African American, in character.

Wynton Marsalis, who will lead the Lincoln Center Jazz Orchestra in an all-Ellington program at Constitution Hall April 26, notes that Ellington's music "always works from an emotional and spiritual standpoint. It is highly accurate: He actually knows how to describe American life in tone."

In a 1947 essay, Ellington wrote that "to my mind, jazz is simply the expression of an age, in music. Think of the terms classical music, romantic music. An entire picture comes to mind – a picture of the way people thought and felt; an expression of human reactions to the conditions under which they lived."

Jazz at Lincoln Center has devoted its year-long season to the Ellington repertoire. As Marsalis notes in "Jump for Joy," a 160-page catalogue created for the centennial program, Ellington is the only American composer capable of sustaining such an extended overview.

A key element in Ellington's work reflected his desire to, as he once put it, "make the listener feel experiences with sound." Ellington heard America singing, sensed the restlessness of its soul. You can hear it in one of his earliest works, 1924's "Choo Choo," the first of many train pieces that grew to include such motion masterpieces as "Happy-Go-Lucky Local," "Daybreak Express" and, of course, "Take the 'A' Train."

Ellington could evoke locales – the early "Creole Love Call," "Harlem Speaks" (one of a dozen tonal portraits of Harlem) and his latter-day "New Orleans Suite." Later, with a world well-traveled as inspiration, he would create, among others, "The Liberian Suite," "The Afro-Eurasian Eclipse," "Afro-Bossa" and "The Far East Suite."

His catalogue includes the romanticism – sweet and sour – of "Satin Doll," "Mood Indigo," "Solitude," "In a Sentimental Mood." The jubilant stomp of "Rockin' in Rhythm," "Braggin' in Brass" and "Cotton Tail." The soul-comforting "Come Morning" and "Reminiscing in Tempo."

And always, there was the celebration, the hard-won recognition for the black experience in America. Throughout his career, Ellington was devoted to "capturing and revealing the emotional spirit of the race." The most famous of Ellington's explorations is "Black, Brown and Beige," which he described as "a tone-parallel to the history of the Negro in America." In this ambitious work, unveiled at Carnegie Hall in 1943, Ellington sought to represent the struggles, hopes and achievements of black Americans from slavery times to that particular present, ending by introducing "the Negro as he is – part of America, with the hopes and dreams and love of freedom that have made America for all of us."

That was the eternal optimist in Ellington. The eternal Ellington is to be found in the memorable melodies and inimitable voicings that continue to define this giant of American music.

While still a high school student in Washington, Edward Kennedy Ellington won a scholarship to the prestigious Pratt Institute of Applied Arts in Brooklyn. He turned it down, opting to stay at home and to continue in a field where he was already earning money and which better addressed his social instincts.

Yet Ellington did become an artist, one working in sound. His studio was the stage and the recording studio. His canvases ranged from three-minute miniatures to the expansive tapestries of his suites. His orchestra was a glorious palette used to paint tonal pictures. "My band is my instrument," Ellington often noted, and its highly individualistic instrumentalists were like tubes of paint, each vibrant hue slowly squeezed out over the years.

A few months before he would have graduated, Ellington dropped out of Armstrong High School. By then he had acquired the nickname Duke – because of his regal bearing – and had begun his musical apprenticeship in the city's restaurants and night clubs, first as a solo pianist, later in small ensembles and society dance bands, and finally, leading the Duke's Serenaders.

Among the Serenaders were drummer Sonny Greer, and saxophonist Otto Hardwick, all of whom joined Ellington in New York in 1923 as the Washingtonians, a sweet, commercially oriented dance band led by saxophonist and banjo player Elmer Snowden. When Snowden left a year later, Ellington assumed the leader's mantle, one he would wear for the next 50 years.

The Washingtonians served a four-year residency at the Hollywood Club, where, Ellington once noted, "our music acquired new colors and characteristics." This was particularly true after trumpeter James "Bubber" Miley replaced Whetsol in 1925 and became the centerpiece of the Washingtonians.

Miley, who pioneered a bluesy "growling" trumpet style that was engagingly conversational, would become the first important individual element in Ellington's tone palette, followed soon after by the "wa-wa" plunger dynamics of trombonist Joe "Tricky Sam" Nanton. In 1926, Ellington wrote his first great composition, "East St. Louis Toodle-oo," which became the Washingtonians' theme song and marked Ellington's transformation from songwriter to composer, and the band's evolution from dance music to jazz.

If the Hollywood Club fired the flame, the subsequent residency at the Cotton Club forged the Ellington sound. For one thing, Ellington's band expanded significantly, from six pieces to 11. Among the key personnel added were baritone saxophonist Harry Carney, a cornerstone of the band from 1927 until Ellington's death, clarinetist Barney Bigardcq and alto saxophonist Johnny Hodges.

Besides writing for the orchestra's nightly national broadcasts, Ellington had to write and arrange music for the Cotton Club stars, as well as creating musical background for the club's exotic stage shows. The need to adapt quickly and in such varied situations certainly sped up Ellington's development. More important, the Cotton Club residency gave Ellington the opportunity to expand the brass and reed sections,think we need "and' to fine-tune his orchestra. And it paid well enough for Ellington to hire key musicians on a long-term basis, which in turn allowed him to write for them knowing they'd be there when he needed them.

The Cotton Club orchestra codified the Ellington sound – a seamless combination of individual solo voices and orchestral voicings – which remained essentially unchanged for the rest of his career. Ellington wrote out everything except solos (which were in time codified as well), and his scores were like internal memos, identifying individual parts not by the specific instrument, but by players' names. He knew exactly what he wanted to hear. So did his musicians.

Clarinetist Barney Bigard once said that Ellington "knew your limits up and down and he would build the things around a given soloist's voice." Ellington's explanation? "You just write for their abilities and natural tendencies and give them places where they do their best."

It's Ellington's handling of tonal resources, his eagerness to move the music in unexpected directions, that make his orchestral works so compelling. He also sought to create something new out of traditional forms, what critic Albert Murray calls �the extension, elaboration and refinement of the traditional 12-bar blues chorus and the standard 32-bar pop song."

Murray writes that it's "not a matter of working folk and pop materials into established or classic European forms but of extending, elaborating and refinishing (which is to say ragging, jazzing, and riffing, and even jamming) the idiomatic into fine art."

Though originally circumscribed by the three-minute time limit of 78s and the expectations of a dance- and ballad-happy public, Ellington soon moved to more ambitious compositions, beginning with 1931's "Creole Rhapsody." In "Beyond Category: The Life and Genius of Duke Ellington," John Edward Hasse notes that from the '30s on, Ellington fought hard to maintain "a balance between what the public wanted to hear and what he wanted to play, between the familiar and the new, between the accessible and the challenging, and between dance/stage entertainment and fine art."

There would be many peaks and valleys in the Duke Ellington journey. Among the peaks: the early '40s, when Ellington began collaborating with composer/arranger Billy Strayhorn, a partnership that elevated the orchestral writing to yet another level; the further fine-tuning of the band during what came to be known as the Blanton/Webster era (after vibrant young bassist Jimmieper hasse book Blanton and tenor saxophonist Ben Webster); the commercial rebirth after a near-riotous performance at the 1956 Newport Jazz Festival.

The last was a final upturn in the fortunes of a band that Ellington somehow managed to keep together for half a century with much the same cast of characters. It triumphed in the swing era; it suffered in the big band nadir of the late '40s and early '50s, and after the arrival of rock-and-roll. At Newport, the audience came close to rioting after tenor saxophonist Paul Gonsalves (egged on by Ellington) delivered 27 screaming blues choruses as a bridge between "Diminuendo in Blue" and "Crescendo in Blue." The subsequent media attention, including the cover of Time, revived the band's reputation, and it was soon working harder than ever, and at higher rates.

The final third of Ellington's career is marked with singular triumphs: the startling soundtrack for "Anatomy of a Murder." The "Sacred Concerts" that Ellington considered his most important work. The jazz adaptations of Tchaikovsky's "Nutcracker" Suite and Edvard Grieg's "Peer Gynt" Suites Nos. 1 and 2. The luminous 1962 tenor encounters, "Duke Ellington and John Coltrane" and "Duke Ellington Meets Coleman Hawkins." Another meeting with modernists, "1962's "Money Jungle," in which Ellington teamed up with Max Roach and Charles Mingus ... And His Mother Called Him Bill," the poignant homage to his creative companion Billy Strayhorn.

Ellington's own legacy bestrides the century.