Sarah Vaughan surely possessed one of the great voices in jazz. It was rich and expressive with a huge range of tones and colors. While attending an arts magnet school in Newark, N.J., she slipped across the Hudson to compete in the famous amateur contest at Harlem’s Apollo Theater. Soon enough, she was opening for Ella Fitzgerald at the Apollo, then her first lasting gig was singing for the Earl Hines Orchestra in 1944. By the late ‘40s, Vaughan was a certified star, and the ‘50s brought her a series of terrific legit jazz dates.

But with great talent comes great responsibility. In the case of a naturally gifted singer, the charge is to sing great material and to value taste over technique. And that is where the grand voice of Sassy Vaughan too often fell prey to temptation. Vaughan’s near-operatic voice reached from contralto to soprano in great swoops, and she took great pleasure in indulging every element of her natural gift, whether it served the song she was singing or not.

On this just-now-released recording from 1971’s Monterey Jazz Festival, Vaughan appears as the climatic act on a night devoted to honoring Norman Grantz’s “Jazz at the Philharmonic” series.  She does seven tunes, some remarkably brief, backed by pianist Bill Mays, bassist Bob Magnusson, and Jimmy Cobb on drums. “The Lamp Is Low” and “There Will Never Be Another You” are tossed off like quickies in less than two minutes each. Vaughan swings them both with ease but it’s a kind of careless ease. The 1:38 of “Another You” contains two key changes. Too much is done too fast and too breezily. These tunes are to jazz singing as a Big Mac is to the hamburger.

The opener, “I Remember You”, takes its time, but Vaughan litters it with audience banter that she squeezes in literally between phrases of the lyric.  She shows off her range and tone unattractively, indulging her vibrato and her more gimmicky vocal tics. Her approach to Monk’s ballad “‘Round Midnight” is altogether better, with her operatic flourishes put in a blues context and a sense of real dialogue with the trio coming through. That said, Sassy wasn’t really known for her blues singing, and the scat feature, “Scattin’ the Blues” is the kind of filler that a terrific artist at her peak should avoid. It was a theme less five minutes of scatting over blues changes. Magnusson and Cobb take sculpted solos that make you realize why Vaughan’s “boo-bee-dooo-beeee-oooo-beee” was just so much futzing about.

Two other tunes advertise the fact that Vaughan was probably bored with this gig. Her take on the Beatles’ “And I Love Him” is serviceable but a textbook example of how jazz singers can ruin pop material. Vaughan takes a simple and compelling melody and thoughtlessly plays with it; “I know this love of mine / will never never never-ne-eh-ve-eh-er die”. So many notes scattered all over the place. “Tenderly” was her “theme song”, and she sings it well. But it’s a gimmick arrangement, starting in mid-tempo, then moving to double-time before an out-of-tempo “big ending”. The result is a collective yawn.

If you wind up wanting to own this live date, it’s going to be for the last 16 minutes, which is a blues jam featuring Roy Eldridge, Clark Terry, Zoot Sims, Lockjaw Davis, Benny Carter, Bill Harris, Mundell Lowe, John Lewis, and Louie Bellson.  This is the “Jazz at the Philharmonic” element, and Sassy’s scatting here is more arresting and interesting from the git-go. After all, slacking in this kind of company is simply bad form. The all-stars turn up the heat and layer on nice improvisational wit (perhaps Davis and Lowe are the winners here?), all of which makes the color-by-numbers set by Vaughan that much more wan by comparison. It climaxes with Terry bringing out his “Mumbles” character to trade scatting fours with Vaughan, a form of good fun that jazz doesn’t provide every day.

Even in this last track, however, you can hear the state that jazz was in around 1971. All these great masters are sounding a mite ragged. Eldridge mutters his solo, Sims gets out of the gates tentatively, and Bill Harris seems to play behind a veil. Vaughan, only 47 years old and at the peak of her powers, is stuck in a terrible rut, replaying old classics on autopilot while taking lazy swats at rock material. A few years later, working with Norman Grantz again on his Pablo label, Vaughan would be set more properly on track, particularly when her virtuosic instrument was intelligently hemmed in by her encounters with Brazilian music and its tradition of under-singing.

But here, before a stadium-sized audience in the era of jazz-fusion, Vaughan and her crew of pre-rock jammers sound like they are rewarming last night’s dinner. Truth was, they didn’t have all that much hunger for it any more.