Ellington could connect all the dots—the social, the modernist, the intellectual, the populist, the personally poetic—for a vision of American music truly epic in scope. Photograph by Marty Lederhandler / AP

Since the nineteen-sixties, there have not been jazz musicians as artistically significant and generally popular as Duke Ellington, John Coltrane, or Bill Evans. Today, jazz music is a miscellaneous collection of wide-ranging and disputed genres that stands to the side of American culture. How did the train go off the tracks? A listen to Ellington and Evans both playing an Ellington standard, “In a Sentimental Mood,” on the same hot Thursday night in New York City—August 17, 1967—offers a few clues. Here is Ellington’s version, at the Rainbow Grill, with the tenor saxophonist Paul Gonsalves, along with John Lamb on bass and Steve Little on drums. And here is Evans’s version, at the Village Vanguard, with Eddie Gomez on bass and Philly Joe Jones on drums.

Ellington, in the twilight of his career, had several long residencies at the Rainbow Grill, a restaurant and ballroom on the sixty-fifth floor of 30 Rockefeller Plaza. Ellington would work on new music during the day (with the passing of his collaborator Billy Strayhorn, in May, 1967, Ellington’s final decade would see a much higher percentage of original music solely from his pen) and, in the evening, would play for dinner, dancing, and listening. This functional gig was a different experience than the glamorous concert tours that the full band made during the year. Yet each night at the Rainbow Grill high society, music fans, and hangers-on came together to see Ellington. You never knew who would drop by: Judy Garland, Tony Bennett, a Rockefeller.

For the summer of 1967, Ellington brought in an octet with the legendary veteran Ellingtonians Cat Anderson, Johnny Hodges, Paul Gonsalves, Lawrence Brown, and Harry Carney, accompanied by a young, mainstream rhythm section. They played the hits and a few minor new pieces. (A bootleg of a complete set came out recently on the Gambit label—an imprint for collectors who don’t mind potential illegalities). Everything is enjoyable, but the highlight is the Gonsalves quartet and “In a Sentimental Mood.”

Ellington packs a whole history of composition into only two and a half choruses. The first chorus is piano in D minor/F major, the “old style,” fairly close to the first 1935 recording. After the “old-style” chorus, Duke modulates to Bb minor/Db major for Gonsalves’s entrance, the same key used for the “new-style” version of “In a Sentimental Mood” tracked with John Coltrane, in 1962. Gonsalves’s greatest fame was authoring twenty-six choruses of shouting blues on “Diminuendo and Crescendo in Blue” at the Newport Jazz Festival, in 1956, a moment that many credit with revitalizing Ellington’s career. However, Gonsalves was also one of the greatest ballad players, and his silky, furry, almost murky legato here is pure delight.

Gonsalves’s mastery is only to be expected, but the sixty-eight-year-old Ellington is still full of surprises. Playing with Coltrane, Ellington’s “new-style” arrangement had a mournful raindrop piano part that was dramatic and distinctive. At the Rainbow Grill, Ellington doesn’t play many of the raindrops but goes all out in rhapsodic style: heavy block chords, cascades, even a long left-hand trill underneath pointillistic right-hand stabs. It would be hard to find ballad accompaniment this busy anywhere else.

Downtown, the vastly influential keyboard artist Bill Evans was enjoying another run at the Village Vanguard. He was a regular at the club, with his 1961 LP “Sunday at the Village Vanguard” well on its way to canonization. When he was in residence, Evans would put a table from the front by the back stairs, come early, and drink coffee while reading the racing news.

In 1967, you could still get a hamburger or a turkey club sandwich at the Vanguard, but there certainly was no dancing. It was a nice, quiet audience for Evans that night. This recording of “In a Sentimental Mood,” which was released on the Verve double LP “California, Here I Come,” has less audience noise than “Sunday at the Village Vanguard.”

The current Evans trio was a mix of new and old. Eddie Gomez was a fresh firebrand in the tradition of Scott LaFaro (the extraordinary bass virtuoso on “Sunday at the Village Vanguard”). The drum great Philly Joe Jones was a familiar Evans associate from their Miles Davis days and the swinging 1958 trio session “Everybody Digs Bill Evans.”

Bill Evans recorded “In a Sentimental Mood” a few times over the years, usually as a ballad, but at the Vanguard that night it was a medium swinger. There are three different takes from three different sets on August 17th and 18th, but the piano part is consistent. Gomez and Jones make all the rhythmic hits and substitute changes with the pianist, but they are also free to offer tasteful commentary. Over all, this is a much more modern and interactive approach to the rhythm section than Lamb and Little with Ellington at the Rainbow Grill. Unlike Ellington’s unwinding scroll, conventional small-band jazz practice dictated an identical “melody in” and “melody out.”

It’s all very hip for 1967, but there was, nonetheless, a faintly homogenous and predictable air from Evans at this point. At the end of the previous decade, Evans essentially co-authored the luminous masterpiece “Kind of Blue” with Davis, but that sense of space and swing was seldom to be heard when he helmed later trios. Still, this comparatively unheralded set is one of the best of later Evans trio dates, simply because Gomez and Jones are so forceful and personal.

Exactly one month before, the jazz world was rocked by the sudden loss of one of its greatest practitioners. For some, the death of John Coltrane meant the death of jazz. Coltrane came from far back in the tradition—he walked the bar as an R. & B. entertainer and knew the bebop giants like Charlie Parker—but his final music was as avant-garde as anything ever recorded. There has hardly been an artist in any discipline who did so much and moved so quickly. When Coltrane died, a fundamental arc of African-American-based instrumental improvisation died with him.

1967 was, of course, a time of great change in American society: the Summer of Love, the Vietnam War, the civil-rights movement, everything else. The rise of rock, soul, and Motown had already put jazz’s relationship to popular culture on notice; the generation gap would seal the deal. A year later, Miles Davis would plug in and incorporate rock, paving the way for the most popular instrumental music of the seventies: fusion—a theatrical jazz-rock synthesis featuring backbeats, electric instruments, and jazz solos. Over all, the history of jazz becomes much more splintered and harder to assess, especially with the forceful trajectory of less popular—but arguably more influential—avant-garde figures who were less overtly concerned with swinging or playing the blues.

The straight-ahead acoustic jazz that generally espoused the values of Ellington and Evans held on mostly as an art music. Masters in that idiom would perform to shrinking audiences in clubs but to bigger numbers in concert halls, especially in Europe. However, the basics of straight-ahead jazz were also being taught to incoming freshmen at an increasing number of American colleges. The influx of students mandated digestible rules. During the mid-seventies, a lead sheet of “In a Sentimental Mood” appeared in “The Real Book,” the most widely disseminated jazz manual ever made, a “fake book” of tunes and chord changes produced by students in the powerful jazz program at Berklee College of Music, in Boston.

If a student wanted to sound like Bill Evans on “In a Sentimental Mood,” he or she could quickly start getting close with the help of a chart in “The Real Book.” The sheet begins with four versions of D minor, “D-, D-(maj7), D-7, D-6.” These aren’t wrong, exactly, but they are far closer to Evans than Ellington, and suggest ways of articulating harmony in a blocky and unmusical fashion, one divorced from the idea and emotion of the original song.