It’s difficult to imagine the singeractress Eartha Kitt and the alto saxophonist Lee Konitz ever working together, but they do have one crucial thing in common: Each takes a distinctive, masterful, and highly personalized approach to the Great American Songbook. Another commonality is that both Mr. Konitz and Ms. Kitt are turning 80 this year, and both birthdays were celebrated this week at the JVC Jazz Festival. Honoring these two amazing artists — both of whom are working at their absolute peaks (the terms “living legend” is such a cliché that it almost seems like an insult) — was a brilliant idea, but mounting both of these tribute concerts on the same night was, well, not so brilliant.

Choosing between these two marvels is like having to choose between Judy Garland and Charlie Parker. Thankfully, I was some what saved because both shows were held at Carnegie Hall — Ms Kitt in the big room at street level and Mr. Konitz in the more inti mate Zankel space downstairs. Mr Konitz’s show also began a half hour later, at 8:30, which made it an easy decision to start with Ms Kitt and then head underground for Mr. Konitz.

I’ve seen Ms. Kitt in cabaret and smaller concert venues, but experi encing her in a huge space like Carnegie is a whole other experi ence. She adjusts her personality to match the size of the room, getting progressively more outrageous as the size of the audience increases Monday night was a glorious sample of the high art of camp — I couldn’t have imagined that any one could ever be so ridiculously over-the-top and yet so subtle at the same time. Segueing seamlessly from sincere ballads (“All My Life”), to mock-ethnic numbers to comedy numbers, Ms. Kitt effortlessly combined first-rate musicianship with masterful shtick of the highest order.

She weaved her big hit numbers in and out of medleys, occasionally prolonging an individual tune to engage in a mock-flirtatious ex change with a male audience member. She has refined and polished “Uska Dara,” for instance, so thoroughly that the vocalized part is gone and all that survives is narration and Terpsichore. This famous Turkish delight culminates in a belly dance; I can’t think of anyone else within 50 years of Ms Kitt who has either the voice or the body for it.

She finished the first set with an extended segment of French songs, but, before it could become tiresome for those of us who failed French, she entered into an hysterical mock-seduction with an young actor playing a waiter. Ms Kitt can belt and bellow and roll her R’s like no one’s business, but she does her most effective singing with just her eyes — she has but to look at us a certain way to get her message across.

For his 80th birthday show, Mr. Konitz played in a variety of settings created for him by longtime collaborator Ohad Talmor, who takes Mr. Konitz’s original tunes and works them into arrangements for different ensembles. I reached Zankel with time to go in Mr. Konitz’s first half, at which point he had already played with several guest stars and was just beginning a segment with a string quartet. He essayed both Debussy (a breathtakingly pure “Reverie”) and Richard Rodgers in a variation on “With a Song in My Heart” that didn’t just elaborate on the chords, but rather deconstructed the melody and scattered it about like Easter Eggs waiting to be found — a few bars here, a line or two there. The first half climaxed with an odd but entertaining rewrite of “Struttin’ With Some Barbecue,” co-starring the great saxophonist Joe Lovano, for three saxes and five strings.

Mr. Konitz returned with two more groups directed by Mr. Talmor. The first was “The New Nonet,” an updated edition of the many medium-sized big bands he’s played with, most famously with Miles Davis. Together the group tackled a extended collage of individual blues themes called “Chromactic Lee.” Mr. Konitz concluded by referencing (but not re-creating) another part of his career: his early big band days with Claude Thornhill and Stan Kenton, with the 17 pieces of the Orquestra Jazz Matoshinos who had flown all the way from Portugal for the occasion. The centerpiece of that section was another extended take on the jazz fundamentals, the Gershwin-inspired “Rhythm Suite,” during which Mr. Konitz again shared solo space with Mr. Lovano.

With all of the guests and special arrangements, I feared I wouldn’t get to hear enough Lee Konitz. But the fear was quickly allayed; he was blowing at his customary brilliant standard, with enough energy and invention to keep going without a let up, even after three hours.

If there was one problem with the show, it was that it was simply too much of a good thing — the number of different groups and guest stars could have been more satisfactorily spread over two entire shows. I stumbled out of the hall, approaching the midnight hour, with my ears and brain fully saturated with two very different musical giants. The best thing about leaving Carnegie Hall so late was that it was the only time I can remember actually being able to get a cab.

wfriedwald@nysun.com