Earl Wild is certainly the world's only pianist to have composed for Sid Caesar, toured with Eleanor Roosevelt and been ranked in dexterity with Vladimir Horowitz. This septuagenarian practitioner of keyboard pyrotechnics, who will play Liszt, and only Liszt, on a formidable program at the Kennedy Center Sunday, has led a life littered with such incongruities.

What other important pianist ever got his start in broadcasting? And what other person of any kind ever found himself dealing simultaneously with Colonel Stoopnagel and Arturo Toscanini?

Today, the mature Wild belongs to a distinctive, and regrettably dwindling, pianistic breed -- the supervirtuoso. Once they were as essential to the magic of the concert hall -- Josef Hofmann, Josef Lhevinne, Rachmaninoff -- as were the divas of that day to the opera house -- Patti, Melba, Galli-Curci.

Those pianists had a control that was uncanny -- listen, for example, to Rachmaninoff's record of Schumann's "Carnaval" -- as well as a stamina that got them through just about any program without flinching. We reflect on that combination today with wonder.

Only a few such keyboard superstars remain -- Wild, Alexis Weissenberg, and Horowitz on a good day. The greatest players of our own era tend to be more contemplative and cerebral. And fine as they are, Wild decries in a recent interview the way younger performers are "dominated by musicologists who frightened them into uniformity."

What is missing, Wild has written, is as much a question of spirit as of substance. He gives this description of a Hofmann recital decades ago in Wild's native Pittsburgh: "His programs were usually on the lighter side . . . The elegance of his playing was always the factor which remained in the listener's mind. Along with interesting tempos, he also had a personal affection for inner voices. I loved hearing his ideas, even though they sometimes bordered on the outrageous."

Very much in that old tradition, Wild has chosen to go on a sort of pianistic binge -- less because he's just turned 70 than because he just feels like it. Sunday's concert is the second in a series of 11, to be followed by sets of three in New York, Chicago and Boston. There will be nothing but Liszt, whose enormous output for the piano is the most consistently daunting for the fingers. Franz Liszt was, of course, the model of the supervirtuoso, and this is the 100th anniversary of his death.

If no other pianist appears to be observing the Liszt anniversary, it may be because there are easier ways to make a living.

Wild describes Liszt as "the main influence throughout my long career" -- if less overwhelming an influence than the composer was to Wagner, his turbulent son-in-law.

Wild, the exemplar of this heroic pianistic tradition, and Wild, the benign raconteur, constitute an unexpected combination. Look for no dramatics at the keyboard; those thundering octaves and shimmering scales never seem to vary in strength or evenness.

Away from his music, Wild is a man of cozy, gentle courtesy -- regaling you with stories arising from his uniquely diverse career. He was the first celebrated pianist to get his start in radio, no doubt, and, also quite probably, the last.

His father died when he was young and at 15 Wild went to work for a Pittsburgh station -- and also became the staff pianist with the Pittsburgh Symphony. Then in 1937 he went to New York to study with two eminent teachers, Egon Petri and Paul Doguereau, and for money joined the music staff of NBC, where he would work for many years.

Some days he wrote arrangements for Colonel Stoopnagel on the Fred Allen show. On others he was staff pianist with the NBC Symphony under Toscanini, arguably the greatest conductor in history.

* "Toscanini's flashes of genius were just so brilliant," says Wild. "And it was all the more special because it was one of those geniuses embedded in a personality who was fully educated." That, suggests Wild, was a reason for Toscanini's titanic temper. "It was directed as much at himself as it was at others."

He remembers, too, another side of the great man. "There was the day he pulled out a handkerchief and said very emotionally, 'Wagner gave this to me.' "

Wild recordings from those days range all the way from his playing the celesta part in Debussy's "Iberia" to a fine Toscanini "Rhapsody in Blue" with Wild the soloist.

* During World War II, Wild was stationed here as a flutist. Also, he ended up touring with Eleanor Roosevelt, playing the national anthem before her speeches. Still with NBC in the '50s, he wrote some of Sid Caesar's musical parodies.

One is struck with the relative smallness of Wild's hands, given the enormous power he brings to his playing. But Wild says hand size can cut both ways.

* He recently observed in an article in Musical America:

"Rachmaninoff's large hands were a blessing of sorts, but also a great problem. In octave playing an over-sized hand is definitely a hindrance. This is the real reason we find so few octave passages in his music. He used his thumbs to great advantage and delighted in the ease with which he could slide from a black note to a white note without the slightest change in texture. Many of his fingerings were unconventional, but they certainly worked for him. Even though the stretch of his hand was enormous, he rarely played a tenth in a large chord in the left hand without using a slight roll. This type of detail work in his playing was the ingredient which supplied the human quality to his performances. It kept the natural sound in the music, as opposed to the constantly precise placement of large chords that produces a mechanical sound."

*If the hand remains an imperfect instrument, Wild says the piano has been perfected about as far as it will go.

And how about the state of new piano music? "The last real composer for the piano was Prokofiev," Wild declares emphatically. Then in an impetuous burst, he adds, "I am convinced that Liszt, with his prophetic endowments, would adore composing with electronic equipment."