A whole tradition of ersatz soul – from Britney and Whitney and Mariah to all the Britney and Whitney and Mariah wannabes on “American Idol” – can be blamed indirectly on Dinah Washington. But that’s a bit like blaming all the second-rate rock stars (are there any other kind?) on Elvis.

Washington (1924-63) was more than a pop singer. She was the first great vocalist to figure equally prominently in the developments of jazz, blues, and popular singing – the progenitor of Joe Williams and Ray Charles, as well as the entire church of soul sisters that began with her acolyte Aretha Franklin. Among female singers, she has been as influential as Sinatra, Charles, and Presley combined.

Washington had such a passionate and aggressive singing style that any attempt to describe what she does with a song requires metaphors so active they’re almost violent: She sings the hell out of a song, she digs into it, she attacks it. Yet in subjecting them to such extremes of feeling, Washington invariably left each a better, richer piece of music than when she found it.

Washington invested pop standards with a blues feeling, sang the blues with a jazz-based improvisational outlook, and could make both jazz and blues material work in a pop context of strings and voices. She was the first artist to begin with a gospel foundation and then spread her wings far enough to conquer all of pop, transcending the boundaries of country music, gospel, R&B, and show tunes. And she was virtually the only pop songstress who when singing a love song could sound tender without getting soft and mushy.

Even more than her colleagues Ella Fitzgerald, Sarah Vaughan, and Carmen McRae, Washington has been well represented in the digital era. The bulk of her recordings were made for Mercury (today owned by Universal Music) from 1946 to 1961; these were issued a long time ago in a Japanese-produced series of seven three-CD sets. The recordings she made in the last two years of her life, however, have not been comprehensively collected until now, with the release of “The Complete Roulette Dinah Washington Sessions” (Mosaic MD5-227, mosaicrecords.com).

For most of her life Washington, unlike Fitzgerald or Vaughan, was promoted primarily to the “race” market (that is, the black audience). It wasn’t until 1959 – after she’d been a star for nearly 15 years – that she had what would today be called a “crossover” hit. “What a Difference a Day Made,” a beautiful song, was originally written in Mexico, but itself had crossed the border in 1934.

Washington sang it in an exceedingly cheesy production masterminded by producer Clyde Otis and orchestrator Belford Hendricks. Following that “success,” Mr. Otis and Mr. Hendricks went on to repeat the formula ad nauseum – giving their star singer good songs but puerile arrangements, with sour-sounding strings and a lot of repetitious, rock-and-roll-like 16th-note patterns.

Washington’s output at Mercury improved considerably after Mr. Otis and Mr. Hendricks left the company, to be replaced by Quincy Jones (whose own years of cheesy pop productions were still in the future). Her 1962-63 sessions for Roulette, however, most under the supervision of Henry Glover, are a major step up.

Roulette, which was generally thought to be controlled by Jewish mafiosi (and operated by a much feared goliath named Morris Levy), had the sense to realize that – despite the success of that 1959 single – Washington was primarily an album artist. It concentrated her efforts toward LPs rather than jukebox 45s.Thus, there is no one hit song that exemplifies Washington in the early 1960s the way “Difference” represents her in the late 1950s.

On a few Roulette recordings, arrangers like Don Costa and Fred Norman seem to have been instructed to give Washington backings that mirror the worst of the 1959-60 material. Yet the incredibly square arrangements, as on “What Kind of Fool Am I,” seem to have impelled Washington to even greater heights of soulfulness. (Think of Ray Charles doing “Ol’ Man River.”)

The Roulette period includes a few bad tunes, too, like “Lingering,” co credited to Washington and “Difference” lyricist (and Ascap president) Stanley Adams, who should have known better. But there are far many more good, offbeat songs, like “Destination Moon” and “Take Your Shoes off Baby (and Start Running Through My Mind).”

The Roulette period began with a set of swinging standards called simply “Dinah ’62.” This included such milestones as “Coquette,” “Miss You,” and “A Handful of Stars.” She followed this with two collections of ballads orchestrated by the great Don Cost. “Dinah in Love” consisted of romantic numbers. “Drinking Again” was a more melancholy gathering, that introduced the titular Johnny Mercer classic and included an aching, blues-infected “Lover Man” and “The Man That Got Away.”

It was 1963 that saw Washington’s single most powerful Roulette set, “Back to the Blues,” as her scorching treatment of “The Blues Ain’t Nothin'” mightily testifies. The underappreciated arranger Fred Norman, who crafted both “Dinah ’62” and its more pop-oriented follow-up “Dinah ’63,” here showed what he could do with an orchestra full of jazz all-stars and blues intentions. “Dinah ’63” combined pop standards with contemporary hits, including an amazingly bluesy treatment of Mercer’s “I Wanna Be Around.”

“Dinah ’63” was, sadly, the last Washington release to come out during her lifetime. Washington’s contemporaries Billie Holiday and Judy Garland were probably the two most self-destructive divas of all time; she didn’t share that quality, yet she died younger than either of them, at 39. It wasn’t narcotics that messed her up, but diet pills. Unfortunately neither Garland nor Presley learned from her example.

When she died on December 14, 1963, Roulette had two albums in the can. The first, eventually issued as “In Tribute,” may have been planned as “Dinah ’64,” since it consists primarily of unestablished songs (like Jimmy Van Heusen’s poignant “Funny Thing”) and, like its annual predecessors, was arranged by Fred Norman. The final project, a third and equally sublime collection of ballads with Don Costa, was released simply and appropriately as “Dinah Washington.”

Although built around classic songs like “Just One More Chance” and “I’ll Never Stop Loving You” (introduced by Doris Day and recorded by Cannonball Adderley), the album also included newer pieces like “Don’t Say Nothin’ at All” by producer Glover (best known for the Ray Charles classic “Drown in My Own Tears”) and Washington’s own “To Forget About You.” “A Stranger on Earth” was a haunting track, which, like “I Wanna Be Around,” had morbid relevance after Washington’s death; it lent its title to a pickup anthology.

Washington was well served by the biography “Queen: The Life and Music of Dinah Washington,” published last summer by Pantheon Books and reviewed in these pages at that time. Author Nadine Cohodas (who also provided the notes for the Mosaic booklet) is an outstanding researcher, who diligently tracked every detail – and every gig – of Washington’s career. Just unraveling the details of Washington’s seven (or is it eight?) marriages would be enough to drive any biographer nuts.

Unfortunately, Ms. Cohodas is not equally skilled as a writer, especially on the subject of Washington’s music and recordings – even though she mentions pretty near all of them. So I’ll be turning back to the Roulette collection much more frequently than the book.

The gem of this Mosaic box is a hitherto unissued 21-minute medley of the kind Washington often performed at the request of fans in her club appearances. The albums of her live dates that Baldwin street music has issued contain several of these medleys, but this is apparently the only time she formally recorded one in a studio. Backed by only flute and piano, Washington runs through half a dozen love songs beginning with “Ill Wind,” and includes “I Could Have Told You” and “Make the Man Love Me.”

I’ve never heard Washington sound so exposed and so vulnerable, and I wish she had done a whole album in this format. Yet this one uninterrupted track is virtually a whole 10-inch LP unto itself: She’s singing for herself here, with an inner concentration she rarely showed elsewhere. When she sings Gordon Jenkins’s “Goodbye,” it’s hard not to think she would be gone a year and a half later. But when she sings, in “For All We Know,” the line “we come and go like ripples in a stream,” you know it’s just a song. An artist like Dinah Washington only comes once in a lifetime.