In the 16th century, Italian harpsichord maker Bartolomeo Cristofori discovered a method by which a hammer struck a string and caused it to vibrate, and the piano was born.

Since then, the piano has made a quantum leap into the computer age.The latest entry is the Boesendorfer 290SE, invented in 1985, where hammers strike strings flawlessly and it doesn't even need a person at the keyboard.

The handmade, shiny black creation contains a device that uses optical sensors that are read every 800th of a second to track the movement of the hammers, keys and pedals.

A blue box the size of a foot locker then turns the information into a digital signal and stores it on an eight-inch floppy or hard disk or an audio cassette.

Finally, using voltage-controlled devices attached to each of the 97 keys - nine more than most pianos - the instrument plays back the piece perfectly on command. An IBM personal computer is used to control the process.

"When you play back on this, there is no speaker . . . The piano is playing again so you're hearing absolutely exactly what the piano has played the first time around because the keyboard is activated to reproduce exactly the performance," said Neil Ratliff, head of the University of Maryland's Music Library, home to one of just three Boesendorfer 290SEs sold in this country.

"The fact that there is no recording of sound is what makes it a spectacular recording medium," he said.

Of the 10 pianos made, one is in England, one is in Maryland, one is at the Massachusetts Institute of Technology and one is owned by a private individual. Six remain unsold.

At 9 feet 6 inches long, it is the largest concert piano in the world, and retails for $85,000, more than twice the cost of many other grand pianos.

When school officials displayed their new purchase, made by Boesendorfer Pianos of Vienna, Austria, a division of Indiana-based Kimball International, at an international piano festival, about a dozen pianists recorded pieces by such composers as Mozart and Chopin. The recordings will be used to teach music students and bolster what Ratliff said is the largest collection of piano recordings in the world.

The music library has about 34,000 piano recordings on everything from records and tapes to about 8,000 old-fashioned player piano rolls dating back to 1904.

"We have every kind of recording ever made on the piano and to us this is another recording device," Ratliff said of the Boesendorfer.

"Our intention and what we've already started doing is inviting major pianists to come and play into our data base so that we are preserving, for all posterity, these particular perfomances," he said.

Ratliff also said the aging player piano rolls, the largest collection of any institution in the world, need to be preserved.

The school's computer science center is working on developing scanners to read the rolls and transfer the information to the Boesendorfer.

The instrument also will help music students by recording their pieces and playing them back so they can hear and see on the keyboard where improvement is needed.

Overall, Ratliff said, the new piano "puts us really on a cutting edge of an incredible new musical technology, a wedding of arts and computer technology. It's an absolutely unbelievable machine."

Still, Ratliff said even this new machine will someday become typical.

"I predict that really 50 years from now, this will be old hat," Ratliff said. "Everybody will have one."