John Diebboll, 54, an architect who discovered a second career as an artist when he began designing fantasy pianos that resembled the Brooklyn Bridge, a diner, or a Murphy bed, died Nov. 23 at his home in Beacon, N.Y.

The cause was brain cancer, his wife, Pamela Koeber-Diebboll, said.

Mr. Diebboll (pronounced DEE-bull) was a longtime member of Michael Graves & Associates, which he joined in 1984 and left in 2007 to found his own firm. He was known for his allegiance to a purist form of modernism and a line of consumer products he designed for Target.

In 1997, Mr. Diebboll found a new outlet for his talents when Sandy Davis, director of the piano-restoration company Klavierhaus, asked him to design a 21st-century piano for a course she was developing in 1997 at Bard College.

For the Bard exhibition he executed a series of drawings, Études, that envisioned the piano in a variety of fanciful guises, updating the 18th- and 19th-century tradition of the art-case piano - custom instruments made for wealthy clients.

Etude No. 30 (Murphy) showed a grand piano that could be flipped up and concealed in a piano-shaped recess in an apartment wall.

Over the years, he produced hundreds of such drawings and prints. None of his designs was built, but his artwork was exhibited in galleries and museums and published in The Art of the Piano (David R. Godine, 2000).

John Joseph Diebboll was born in Detroit and grew up in Washington, Mich. After earning a bachelor's degree in 1978 from Bennington College, he joined the architectural firm of Conklin & Rossant. There he worked on the master plan for Tanzania's new capital, Dodoma, and on the restoration of Brooklyn Borough Hall.

Later, with Graves, he helped design numerous schools, libraries, hotels, and private residences. - N.Y. Times News Service