Frank Sinatra circa 1956. (Herman Leonard)

When it comes to the birth of American geniuses, 1915 was a very good year. This year marks the centenary of Orson Welles, Arthur Miller, Saul Bellow and, on Saturday, the guy who gave eternal life to the Great American Songbook — Frank Sinatra.

Bellow and Sinatra also have something in common more important and remarkable than their birth year, their affinity for fedoras, their decades-long political drift from left to right and their tempestuous personal lives. It wasn’t until 1953 that each found his voice.

The Adventures of Augie March,” the Bellow novel published that year, marks the real beginning of Bellow’s distinctive contribution to literature. What “Augie” had that Bellow’s previous writing lacked was a voice new to American letters: serious, wiseass, street-smart, discursive, digressive, New York intellectual and racetrack tout rolled into one. Bellow’s voice — as distinct from those of such earlier urban chroniclers as Theodore Dreiser and James T. Farrell — was that of the smart guy in and of the city, a voice that enabled him to convey, compellingly and authoritatively, the comedies and tragedies of mid-20th-century American life.

Sinatra’s voice did much the same, and, like Bellow, he didn’t find it until his mid-30s. His annus mirabilis was also 1953 — the year he turned in an Oscar-winning performance in “From Here to Eternity,” but also, more importantly, the year he moved from Columbia to Capitol Records, where he found better microphones and a brilliant arranger, Nelson Riddle. But the Sinatra who came to Capitol was no longer the youthful crooner of the Tommy Dorsey and Columbia years. He’d loved and lost Ava Gardner, lost his teenage fan base, even briefly lost his voice. He’d been shattered — and, somehow, strengthened.

The time for smooth ballads was over, finished. Sinatra now sang of loss and exultation, of deep, often primitive emotion (he had plenty of that, right on the surface) informed by experience, style and judgment (he had even more of those). The very first number he recorded with Riddle was Harold Arlen and Ted Koehler’s “I’ve Got the World on a String,” sung with a new mixture of authority and controlled abandon, elongating the soft consonants (nobody stretched the letter “N” like Sinatra), swinging the delivery with a paradoxical loose precision. “I’m back!” Sinatra exulted when the session ended. Was he ever.

“I’ve Got the World on a String” had been around for two decades by the time Sinatra and Riddle got to it. While some of Sinatra’s standards were written (usually by Sammy Cahn, Jule Styne and Jimmy Van Heusen) specifically for him during the Columbia and Capitol years, more had been encased in the Songbook for a decade or more when Sinatra turned to them. Cole Porter’s “I’ve Got You Under My Skin” was first sung by Virginia Bruce in a 1936 MGM musical; Arlen and Johnny Mercer’s barroom elegy, “One for My Baby (And One More for the Road),” by Fred Astaire in a 1943 RKO musical.

What Sinatra brought to those and countless other songs that hadn’t been brought before was an acting genius expressed musically. He’d study the lyric even before he’d look at the sheet music, burrow into the letter and spirit of the words. He had a bias for the lyric, stretching or snapping (but always clearly enunciating) the words to convey their fuller impact and intent. No one ever served great lyricists like Porter, Mercer, Larry Hart or Yip Harburg better, or great composers like Arlen or Richard Rodgers.

“Words make you think a thought,” Harburg once said. “Music makes you feel a feeling. But a song makes you feel a thought.” No singer ever made you feel a thought more deeply than Sinatra.

The authors of the Songbook, of the classic songs of the ’20s, ’30s and ’40s, were city guys (and the occasional gal) who brought the blue notes of black music, the minor strains of Hebraic chants and the wit of sidewalk culture into the American mainstream. This mix of vulnerability and assertion peculiar to lives of immigrants and their children, of Jews and blacks in a nation whose dominant culture had been uniformly Christian and white, was a defining feature of the work of the Songbook’s creators. It took an immigrants’ kid off Hoboken streets to give it its definitive voice — like Bellow’s, that of a minority, so brilliant, so compelling that it redefined the American sound and sensibility.

That’s no small achievement. Happy birthday, Frank.

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