One of the many remarkable things about the pianist Keith Jarrett is that for a musician who has done as much as anyone to promote the cause of spontaneous, improvised music, nearly everything he does is calculated. Not only that, it’s calculated to produce as much tension as the human psyche can absorb.

Think of Mr. Jarrett as a juggler who keeps spectators on the edge of their seats by throwing three knives in the air and keeping them there for as long as possible. Unlike a juggler, though, Mr. Jarrett keeps piling on the tension throughout numbers that go on individually for at least 10 minutes. His concert at Carnegie Hall on Thursday night, as part of the JVC Jazz Festival, featured a full two-and-a-half hours of just piano, bass, and drums. (Mr. Jarrett is also a long-distance runner in the sense that this trio, with the bassist Gary Peacock and the drummer Jack DeJohnette, is nearing its 25th anniversary.)

That tension was palpable even as Mr. Jarrett walked out on the stage. Perhaps the key lesson he learned from his experience with Miles Davis, with whom he played from 1970–71, was the concept of reverseshowmanship, or playing hard to get — to ignore the crowd and present himself as downright hostile. On Thursday, the worst that Mr. Jarrett did was castigate the “stupid people” who insist on taking his picture with camera phones.

Although Mr. Jarrett has absorbed a lot from such piano predecessors as Bud Powell and Bill Evans, sometimes it seems as though his greatest influence is Alfred Hitchcock. His first tune started solo, a wash of impressionistic harmonies rendered ad lib. But even after he kicked it into tempo, he refused to give us a hint as to the identity of the melody. Rather, Mr. Jarrett dangled hints of it here and there, leading us ever forward like horses behind a carrot. He played faster and faster, without ever dropping the other shoe and letting us in on the tune.

As it happened, I was prepared: I had just watched the DVD of the Jarrett Trio live in Japan in 1986, so I was quick to recognize the piece as his arrangement of Cole Porter’s “All of You.” But I could sense the craze building in the crowd as he pushed onward, finally to resolution.

Mr. Jarrett’s fast, boppish numbers are dazzling and even thrilling; his blues originals, “One for Majid” and “Is It Really the Same,” are funky and moving (in the physical if not emotional sense), and his rearrangements of standards, such as an Afro-Cuban “I’m a Fool To Want You,” are smart and engaging.

The blues give him the best opportunity to showcase his famous body contortions, which become a sort of interpretative dance. Thelonious Monk used to dance when others in his quartet soloed, but Mr. Jarrett does Monk one better by dancing in the middle of his own solos. The pianist also displayed a propensity for time in contrasting tempos, beginning the second half of the show with Dave Brubeck’s “It’s a Raggy Waltz” and Snow White’s “Someday My Prince Will Come.”

But it’s Mr. Jarrett’s slow ballads — such as “Yesterdays” and “God Bless the Child,” both performed on Thursday — that are something else entirely. His harmonies are lavish, ornate, and beautiful without being fussy. He stretches everything out as long as it can be stretched before resolving it, giving us chorus after chorus of tense chords that cry out for resolution, like so many sinners in search of salvation.

As usual, Mr. Jarrett ended early, leaving time for three encores (another calculated move). The ballad highlight was the official closer, Cy Coleman’s seldom-heard “I’m Gonna Laugh You Right Out of My Life,” which surged into one of Mr. Jarrett’s mega-extended, neverending codas — not that you’d ever want them to end. This particular coda went on so long that it could have met a nice girl, settled down, and had kids before it was finished.

Even in those cases when Mr. Jarrett gives us the melody straight away — as on “Stars Fell on Alabama” — he prolongs it in the most suspenseful way, extending it and revealing the tiniest bits at a time, a striptease artist slowly removing his gloves. On this tune, Mr. Jarrett made us cling to every note like drops of water in the Sahara. Had I realized that Alabama could be so beautiful, I would have never left.

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There was one other big piano event at this year’s JVC Jazz Festival, an evening with Kenny Barron and Elaine Elias Sunday night at the Allen Room (in Rose Hall), produced for JVC by JazzForum.

I was disappointed when I realized the show would not follow the format of JazzForum’s 2005 teaming of Hank Jones and Barry Harris on two pianos. For that performance, the two keyboard giants spent a lot more time playing four-handed duets together, whereas Sunday’s show was mostly two individual sets — fine though they were — strung together with only three meetings between the featured stars.

Mr. Barron played two standards and a blues, beginning with his finely developed solo reconstruction of “I’m Getting Sentimental Over You.” Ms. Elias played and sang mostly Brazilian songs, as well as a rare Bill Evans tune.

But what I’ll remember most about the evening are the boy-meets-girl dual-piano pieces that utilized a full 18 feet of Concert Grand Steinways: a dense yet swinging “Way You Look Tonight” in the middle of the show and, as the encore, Jobim’s “Wave,” done à la 52nd Street, not Rio De Janeiro.

Two-piano duets often go for subtle arrangements, but here the twin keyboardists generated as much energy and heat as possible, merging into a formidable two-person band. On the announced closer, “Just in Time,” the duo built to a furious chorus of traded fours, in which Mr. Barron and Ms. Elias fired notes at each other in rapid motion and, miraculously, never lost track of Jule Styne’s melody in the process.

THIS WEEK AT THE JVC JAZZ FESTIVAL

TUESDAY, JUNE 26

Tonight, Carnegie Hall will play host to the only jazz-free night of the 2007 JVC Festival, in which the celebrated Cape Verdean diva Cesária Évora shares a bill with the indie pop duo the Bird and the Bee, who will perform their “sunshine-drenched, semi-psychedelic ditties.” This show is a nobrainer. Disappointingly, the announced celebration of the Benny Carter Centennial, which promised to be the highlight of the whole fest, has been cancelled.

WEDNESDAY, JUNE 27

While the pianists Geri Allen and Anat Fort play the Studio Museum in Harlem and the Rubin, respectively, and the fusion violinist Jean-Luc Ponty plugs in downstairs in Zankel, the great bassist Ron Carter seizes the day in the big room at Carnegie for his 70th birthday. No fewer than four ensembles have been announced: a duet with the guitarist Jim Hall, a trio with the pianist Mulgrew Miller and the guitarist Russell Malone, and a “new” quartet with Stephen Scott, Payton Crossley on drums, and Rolando Morales on guitar. Still, the main attraction for most of us will be the reunion of Mr. Carter with three fellow veterans of Miles Davis’s great bands of the 1960s: the pianist Herbie Hancock, the saxist Wayne Shorter, and the drummer Billy Cobham.

THURSDAY, JUNE 28:

Giving us a little breathing room while we prepare for the climactic concert on Friday, JVC is mounting two comparatively lower-key events (and nothing at Carnegie). At the Citicorp Plaza, the International Women in Jazz organization is mounting an afternoon concert spotlighting two younger female instrumentalists — the bassist Sherry Luchette and the molto buono gusto Italian tenor saxist Ada Rovatti. In the evening, the veteran trombonist Roswell Rudd (who has several new releases out) is launching a threenight stand at Jazz Standard, which is also falling under the JVC Jazz Fest umbrella.

FRIDAY, JUNE 29

The last big show of the Festival is the all-star 70th birthday salute to the highly accomplished jazz-pop singer and NEA Jazz Master, Nancy Wilson. Costars include old friends Mr. Herbie Hancock and Ramsey Lewis, the young and highly entertaining violinist Regina Carter, and the contemporary vocalists Kurt Elling, Nnenna Freelon, and Dianne Reeves. Considering that the marvelous Ms. Wilson announced her retirement in 2003 (as far as I know, she has not performed in New York in the last four years), this is not a show to be missed.

SATURDAY, JUNE 30

After the big all-star concerts on Wednesday and Friday, this evening seems a bit anticlimactic. For the last night of the Fest, Carnegie will host a double bill of fusion banjo faves Béla Fleck and the Flecktones and the bluegrass group the Del McCoury Band. If you’re a fan of quasi-jazz-country-gospel-pop played on strings, this will be just the ticket.