Why is it that the only movies with any decent music in them these days are brooding historical dramas about the dark, evil days of the Cold War? I’m referring to “Good Night, and Good Luck,” which prominently featured Dianne Reeves, and “The Good Shepherd,” which did the same for Ann Hampton Callaway.

Perhaps it’s because Ms. Reeves and Ms. Callaway are two of our strongest and most talented links to history. When these two übertalented singers first emerged, the giants of jazz’s golden era were still on the circuit. But in the years since Sarah Vaughan and Ella Fitzgerald died, Ms. Reeves and Ms. Callaway have dutifully taken the torch, growing into the finest representatives of the art of contemporary singing.

Both appeared in concert this weekend, Ms. Reeves at the Allen Room as part of Jazz at Lincoln Center’s long-running “Singers Over Manhattan” series, and Ms. Callaway at St. Peter’s as part of the first annual International Women in Jazz Festival. It was also clear from both recitals that Ms. Reeves and Ms. Callaway view the performing of jazz, as well as the Great American Songbook, more as a privilege than a responsibility.

During the long-running arc of her career (she made her first recording more than 30 years ago), Ms. Reeves has increasingly made wordless vocal improvisation an important part of her music. At her last big concert in New York, as part of the opening of Frederick P. Rose Hall in 2004, Ms. Reeves seemed to be singing more scat syllables than verbal lyrics. Since then, she has tapered off such heavy use of the technique — sonically pleasing as it is.

The soundtrack album to “Good Night, and Good Luck” was notable in that Ms. Reeves sang all the words and music “straight,” with no improvisatory embellishment; now, even in her own sets, she’s scatting less often but no less effectively. At the opening show on Friday night, she delivered her second tune, Benny Golson and Jon Hendricks’s “Social Call,” without any improv, revealing that even a musician endowed with her power knows well the value of simplicity.

Most singers divide their repertoire between fast swingers and slow ballads, but nearly all of Ms. Reeves’s songs are in the same medium beat, distinguished more by dynamics — loud and ecstatic, quiet and melancholy — than by tempo. Ms. Reeves isn’t necessarily lyric specific — she doesn’t try to make every word come alive and paint a vivid picture in the listener’s head, the way Billie Holiday and Frank Sinatra did; rather, like Ella Fitzgerald, Ms. Reeves is so filled with warmth and emotion that we can’t help but feel exactly what she wants us to.

“One for My Baby” was delivered as a modal blues (featuring bassist Reginald Veal and drummer Greg Hutchinson’s elegant brushwork) more in the spirit of Miles Davis than Sinatra, while folk-rocker Leonard Cohen’s “Suzanne” (learned from Nina Simone, I would wager), supported by pianist Billy Childs, reached an erotic peak of emotion that was at once euphoric and melancholy. In Mr. Cohen’s song and with Alec Wilder’s text to “A Child Is Born,” Ms. Reeves found emotional depth I’ve rarely heard in either song.

In the last few years I’ve grown accustomed to facing Ms. Callaway with at least a bassist and a drummer, and, sometimes, a pianist and even the full Diva Orchestra. Her recital on Saturday took me back to hearing her in small clubs in the early 1990s, when she worked with just her own piano — she is an excellent accompanist for herself, and I generally prefer it when she keeps her own counsel, piano-wise. The St. Peter’s show also evoked her early, informal days in East Side saloons in the way she stretched out and chatted with the crowd as if we were in her living room rather than a church atrium, and in how she did vocal impressions of canonical singers as well as every instrument in the orchestra. She was so musical and entertaining, that even the considerable drawbacks of St. Peters — i.e. the bizarre acoustics, worse lighting, and a piano that went out of tune by the second half — could hardly come between her and us.

Ms. Callaway obviously realized that for up-tempos she would have needed a rhythm section (not that it would have mattered, since basses and drums tend to get lost in the church acoustics), so she sprinkled her show with just a few of these, for the sake of variety and mostly from her current album, “Blues in the Night.” Instead, the nearlytwo-hour performance was wisely focused on slow love songs — near the start, she did a wonderful “Proximity Medley” of “The Nearness of You” and “You’re Nearer” — and she found infinite diversity even while remaining in this format.

Ms. Callaway also illuminated “How Deep Is the Ocean,” a song about the extremes of physical distance, with miraculously high topnotes and resonant pedal tones, and she climaxed with “Blue Moon,” which was re-harmonized with Gospel chords that fit the clerical setting. She also sang “Come Rain or Come Shine,” with soulful, Ray Charles-inspired melismas, though I prefer the more undecorated version she sang for “The Good Shepherd.” When Ms. Callaway sings the melody as close to as written as possible, she flies within the orbit of the great Jo Stafford, and, in my book, that’s extravagant praise indeed.

This weekend, Dianne Reeves and Ann Hampton Callaway showed that the legacy of Sarah Vaughan and Ella Fitzgerald is in good hands. When Ms. Reeves finished her show (which, at less than an hour, was too brief ), everyone seemed pleased and not just in the capacity crowd in the Allen Room; I could swear that the most famous resident of Columbus Circle, the statue of Christopher Columbus, had turned to gaze at Ms. Reeves and was snapping its fingers along with the rest of us.

wfriedwald@nysun.com