There are entertainers who tell jokes, spin plates, or juggle bowling balls. There are also some trickster-showmen who can make the jack of spades jump out of a brand-new deck of cards and squirt cider in your ear. Others play the piano. Indeed, in the early days of jazz, piano playing was a form of hustle, which is why it’s no surprise that jazz’s first great pianist-composer, Jelly Roll Morton, prided himself on his accomplishments as a hustler and procurer as much as a musician — it was hard out there for a pimp.

There are two outstanding pianist-showmen in town right now, one a veteran — Michel Legrand at Birdland, through Sunday — and the other a relative newcomer — Tony DeSare at the Oak Room, through March 17. Both do other things besides play the piano; Mr. Legrand dips into the vast catalog of famous songs he has written through the years and Mr. DeSare sings and does other crowd-pleasing turns — but both are essentially keyboardist-entertainers.

This tradition not limited to jazz (witness Liberace or Jerry Lee Lewis), but it tells us something that one of the most effective ways to entertain an audience is to take a familiar melody and jazz it up or reshuffle it like a pianistic card shark.

Most people come to hear Mr. Legrand, who celebrated his 75th birthday two weeks ago, because they love his songs. He may be one of the most famous living songwriters (on a par with Stephen Sondheim, Paul McCartney, or Bob Dylan), yet he never once utters, “And then I wrote…” — the mantra of the performing composer. He doesn’t seem to want to impress us with his list of hits, but rather with his skills on the keys. He also refrains from rattling off his list of Oscar and Grammy wins, but he does make sure we know that he collaborated on two projects with Miles Davis (and plays two numbers from the second, the 1990 film score of “Dingo”).

Mr. Legrand presents himself as a serious jazz pianist — with a rhythm section of Ron Carter on bass and Lewis Nash on drums to support the claim — who just happens to have composed several dozen of the melodies that the world loves best. And in that guise, he does things to his own tunes that would cause a traditional songwriter, like Irving Berlin or Jerome Kern, to cringe.

For example, he reinterprets “How Do You Keep the Music Playing” as if to answer the titular question, playing it faster than any singer would do it with a lot of baroque ornamentation. Mr. Legrand did not, at least in the late show this week, parade out any of his familiar blockbusters, and the only tune he played and sang mostly straight was “I Was Born In Love With You,” a lesser-known gem that accomplished vocalists ought to try more often. By rending it as simply and emotionally direct as possible — as opposed to the virtuoso showpieces around it — he made it that much more moving.

Mr. Legrand climaxes his show with a brilliant showpiece that serves as a tour de force for all three of his identities — jazz pianist, popular composer, and trickster extraordinaire. He speaks of a dream he had recently (funny, he had the same dream in January, shortly before he appeared at the French Institute Alliance Franççaise as part of the French Quarter Jazz Festival) in which legendary jazz pianists appeared before him and offer their interpretations of “Watch What Happens,” one of his earliest international hits.

In a bit similar to John Pizzarelli’s series of impersonations of pop stars doing the trivial “I Like Jersey Best,” Mr. Legrand approximates all manner of jazz giants rendering his tune in their own ways: Art Tatum with breakneck speed and dazzling arpeggios, Dave Brubeck with a 9/8 blue rondo, Erroll Garner (who really did record it, on a 1973 album appropriately titled “Magician”) with rollicking bass riffs and incidental moaning, Fats Domino as an eight-to-the-bar boogie-woogie, George Shearing with block chords, and Count Basie with a three-note tag.

Approximating the styles of the immortals, both as a learning exercise and as a homage, is apparently a staple of keyboard-centric showmanship. In his show at the Oak Room, Tony DeSare includes an unaccompanied stride piano solo in the manner of Fats Waller in his rendition of “Gee Baby, Ain’t I Good to You” and also references Garner in the middle of his Sinatrainspired “Birth of the Blues.” He also does a hilarious recreation of himself as a teenager garbling Elton John’s “Bennie and the Jets.”

But the overall style of Mr. De-Sare’s music is rooted in two of the most influential combos of the 1940s — the Nat King Cole Trio and Count Basie’s All American Rhythm Section. Mr. DeSare is especially fortunate to have, as the driving force of his quartet, Bucky Pizzarelli, the world’s greatest living guitarist. Mr. Pizzarelli learned directly from Cole’s Oscar Moore and Basie’s Freddie Greene, so in a sense, Mr. DeSare is helping the guitarist relive his youth.

Mr. DeSare is an increasingly polished vocalist. He follows “Bennie” with “If I’m Not Near the Girl I Love” as a showcase for his ability to illuminate E.Y. Harburg’s phantasmagorical quadruple-rhyme bridge. He also shines as an interpreter in two voice-and-guitar duets with Mr. Pizzarelli, namely “Memories of You” and “How Deep Is the Ocean.” Finally, he expresses himself as a composer, although on “Let’s Just Stay In,” he reaches for a sophistication (aspiring to both Cole Porter and Dave Frishberg) that as yet exceeds his grasp. He does better on the simpler, Renaissance-like “How I Will Say I Love You.” But it’s those feats of keyboard illusion, such as harmonic sleight of hand, that are the heart and soul of his show.

Just as Mr. Legrand combines “Watch What Happens” with “A Train” (both songs are based on the same chord progression), Mr. DeSare merges “Back Home Again in Indiana” with its bebop variant, Miles Davis’s “Donna Lee,” the latter melody performed as a whistling solo by bassist Mike Lee.

Mr. DeSare especially excels at singing songs of youth and innocence, as in “Baby Dream Your Dream,” which he renders with a marvelously propulsive four-four thanks to Mr. Pizzarelli and drummer Brian Czach, but little of the irony emoted by the Fandango girls in “Sweet Charity.” Yet he also adapts Prince’s “Kiss” (pretty much a straight-up blues) into a 1940s idiom, and, on his fine new album “Last First Kiss” (Telarc) he transforms Carole King’s defiant “I Feel the Earth Move” into a tender love song — when he tells a girl to act her age and not her shoe size, he knows well what he’s talking about. Mr. Legrand’s music is timeless, and, as the younger Mr. DeSare shows, one of the greatest feats of a piano prestidigitator is bridging generations, even as both performers leave us happily shaking the cider from our ears.

wfriedwald@nysun.com