Listening to 70-year-old Duke Ellington recordings on your iPod is not nearly as incongruous as it might seem. As a new boxed set, “Duke Ellington: The Complete 1936–1940 Variety, Vocalion, and Okeh Small Group Sessions” (Mosaic Records), makes clear, great music can often be inspired by technological innovation.

Indeed, the jukebox may well have been the iPod of the 1930s, in that it served to disseminate the best popular music of the era and gave composers and performers like Ellington the impetus to create some of their most durable work.

Coin-operated phonographs in public places date back to the 19th century, but the concept was enthusiastically reborn with the end of Prohibition in 1933 and the beginning of the swing era two years later. At the depth of the Great Depression, most Americans couldn’t afford to pay the cover charge at a big-city nightclub, or even plunk down 75 cents for a new record. But they could drop a nickel in the slot of a jukebox to dance and drink in the roadhouse establishments that proliferated once liquor regained legal status. The juke joints helped make superstars out of singer-playerfunsters like Fats Waller and Louis Prima, and inspired Ellington and his longtime associate Irving Mills to reach for a piece of the action.

At the time, Ellington (1899–1974) was already known as the aristocrat of the jazz world, the first black bandleader to be regarded as a serious composer by white Americans and, increasingly, by Europeans as well. Not yet 40, Ellington was already the industry leader for American music, a position he would occupy, despite changing trends in jazz, for the rest of his life.

Mills was already Ellington’s manager and music publisher, and now, with the jukes reviving the long-dormant phonograph industry, he sought to become Ellington’s record producer as well. As annotator and engineer Steven Lasker explains in the Mosaic Records booklet, when Ellington’s contract with Brunswick Records expired at the end of 1936, Mills quickly formed a new recording operation and signed Ellington to it. By 1937, Mills was releasing discs by the full Ellington Orchestra on the 75-cent label Master Records, as well as tracks by various smaller Ellington units on the 35-cent Variety Records.

The latter recordings were released under the names of the band’s four biggest instrumental stars: the cornetist Rex Stewart, the trumpeter Cootie Williams, the clarinetist Barney Bigard, and Ellington’s most famous sideman, the alto saxophonist Johnny Hodges. Though each of these sidemen served here as leaders and also wrote much of the material, it was understood that these were Ellington productions, with the Maestro playing piano and contributing compositions and arrangements to most of the dates.

By the 1940s, when Ellington began regularly turning out extended compositions, such as his famous suites, his bread-and-butter three-and-four minute stand-alone works were occasionally referred to as “miniatures.” The small band works of 1936–40 are even more miniature, and while they could be described as “Chamber Ellington,” they are not like any other chamber music, be it jazz or classical. They don’t sound like the Benny Goodman Quartet or the baroque-informed jazz-classical hybrids of either Raymond Scott or John Kirby.

Ellington, who harbored a lifelong aversion to the notion of closure, was continually tinkering with his basic material, and with these small groups, he tended to revise and revisit perhaps even more than with his full orchestra. When, at the end of 1936,the valve-trombonist Juan Tizol brought Ellington a distinctive F-minor melody, Ellington tried placing it in two disparate musical locales — first and most successfully as the mystical “Caravan,” then reworking it into the somewhat less exotic “Alabamy Home.” Likewise, another melody turns up here both as a funky dance groove in “Have a Heart” and as a contemplative ballad in “Lost in Meditation.” There are also many typically sophisticated and swinging permutations on the blues, most spectacularly the premiere recording of Hodges’s perennial showstopper “Jeep’s Blues.”

Although the main focus of this release is on pure instrumental compositions by the Duke and his men, there are also many pop songs, by Ellington and others, usually also published by Mills. Regrettably, there is only one session featuring Ellington’s superlative vocalist, Ivie Anderson, but the most notable guests on these dates are a parade of obscure but winning boy and girl singers, such as Scat Powell, Leon LaFell, and the amazingly hip female swingster, Jerry Kruger. There are also two titles featuring future star crooner Buddy Clark, who is surprisingly loose and jazzy on “Sailboat in the Moonlight” and “You’ll Never Get to Heaven.”

Mills’s experiment with running his own label lasted only a year, not long after which Ellington severed his relationship with the ambitious publisher-manager (whose typical tactic was to put his name down as co-composer of nearly everything Ellington wrote). Yet the Maestro continued to record prolifically in small group settings as well as in his full orchestra for the rest of his long career, which spanned nearly 50 years. Ellington was one of jazz’s great pianists, but, as his son, Mercer, famously noted, “The orchestra is his instrument.” This essential boxed set shows that the small group was, too.

wfriedwald@nysun.com