Sujatri K. Reisinger, who sells pianos for a living, has been working the phone, trying to borrow a few. Actually, more than a few: 21 grands, for a total of 1,848 keys. And all built by a relatively obscure Italian manufacturer that makes only 100 instruments a year.

Mr. Reisinger, an owner of Klavierhaus, a piano shop on West 58th Street between Broadway and Seventh Avenue, is looking for the pianos that will star in a concert during the opening week of the 15th season of the Winter Garden at the World Financial Center.

The pianos he is looking for are not Steinways, not Mason & Hamlins, not Baldwins, but Faziolis. So far, he said, he is two-thirds of the the way toward meeting his goal.

Faziolis are shiny, expensive instruments made according to the designs of Paolo Fazioli, a concert pianist who went into engineering before he discovered his life’s work: trying to reinvent the modern piano. 21Pianos_Winter_Garden_2

The most talked-about of his company’s six models is the F308, at least one of which will be among the 21 pianos Mr. Reisinger is rounding up. At 10 feet 2 inches and $140,000, it is 14 1/4 inches longer and almost $50,000 more expensive than a Steinway concert grand.

It has an extra pedal, for very, very soft playing. Whether it is needed for one piece that will be played on Sept. 25 — the world premiere of ”Threnodia for 21,” a piece by Daniele Lombardi, an avant-garde Italian composer, and dedicated to the victims of the Sept. 11 attacks — remains to be seen.

Also on the program is the first performance in this country of Mr. Lombardi’s Sinfonia Nos. 1 and 2 for 21 Pianos.

In some passages of ”Threnodia,” Mr. Reisinger said, the pianists are to stand up, reach into the pianos and strum the strings. In other passages, they are to pound the keyboards. It will be something to see — and that, Mr. Reisinger said, is just what Mr. Lombardi had in mind.

”He created a work that’s important three-dimensionally, with the movement of the conductor and the movement of the artists,” Mr. Reisinger said. ”It is a sculpture in the making, right on the spot.”

Before there can be sculpture, or music, there must be 21 pianos. Mr. Reisinger, who sells Faziolis along with Steinways and other pianos that he and his technicians have rebuilt, decided to round up 21 Faziolis — something he has wanted to do since meeting Mr. Lombardi in 1997 — and approached the World Financial Center about the holding the event. 21_Pianos_Winter_Garden_3

”When I told Paolo, he said it’s impossible,” Mr. Reisinger said. ”He’s never seen 21 Faziolis together in his life.” But he will, assuming Mr. Reisinger succeeds: Mr. Fazioli has promised not only to attend the concert, but also to autograph each piano that is used.

Mr. Reisinger has been calling other Fazioli dealers in this country and in Europe. As of last week, he said that he had commitments for three Faziolis from Boston, four from Virginia and four from Utah, maybe five.

Rick Baldassin, a Fazioli dealer in North Salt Lake, said the number depended on whether his wife, Cindy, would let him send the 7-foot-6 Fazioli in their living room along with four from their showroom.

21_Pianos_Winter_Garden_1‘I’m inclined to believe that she’s O.K. with it,” Mr. Baldassin said. ”You can imagine. It’s one thing to send the children from the store. It’s another thing when you’re sending the one from your house, but why not?”

Debra Simon, the executive director of the World Financial Center’s arts and events program, said the 21 pianos would be the largest collection of pianos played at the same time in one place since the 1939 World’s Fair. And those pianos were uprights, not grands.

Mr. Lombardi knows what it is like to have more than one Fazioli on hand. Mr. Reisinger said Mr. Lombardi once asked Mr. Fazioli to send him two. Mr. Fazioli did so, Mr. Reisinger said, but only after asking this question: ”Can’t you compose something for 3 or 4 pianos instead of 21?”

Photo: Debra Simon, the director of the World Financial Center’s arts and events, and Sujatri K. Reisinger, an owner of Klavierhaus, a piano shop. (Photo by Nicole Bengiveno/The New York Times)