The cause was heart failure, said Arne Glimcher, chairman of PaceWildenstein, the Manhattan gallery that represents Rauschenberg.

A painter, photographer, printmaker, choreographer, performer, set designer and, in later years, even a composer, Rauschenberg defied the traditional idea that an artist stick to one medium or style.

Together with painter Jasper Johns, with whom he was romantically linked, Rauschenberg was the most important American artist to emerge into prominence in the 1950s.

Those most famous creations would be his "combines" -- giant collages of found objects that hover somewhere between painting and sculpture.

Rauschenberg made 162 combines between 1954 and 1964, and they remain the most highly regarded and influential body of work by the unusually prolific artist.

In the early 1970s, the great art historian and critic Leo Steinberg said Rauschenberg had "let the world in again."

The largest collection of combines -- 11 works -- is housed in Los Angeles at the Museum of Contemporary Art. Chief curator Paul Schimmel organized an exhibition of 70 combines in 2005, which traveled to New York's Metropolitan Museum of Art and to museums in Paris and Stockholm.

Although he is famous for his combines and silk-screen paintings, it is also significant that Rauschenberg was the last artist who believed that art could change the world -- and he devoted more than a decade to proving it.