During his half-century career, Robert Wise (search) — who died of heart failure Wednesday at 91 — was nominated for seven Academy Awards, had hits in a variety of genres and worked with Orson Welles on "Citizen Kane." But he gained his greatest acclaim — and four Oscars — with the big-budget productions of "West Side Story" (search) and "The Sound of Music," two of the most popular musicals of all time.

In all, Wise directed 39 films, ranging from science fiction ("The Day the Earth Stood Still") to drama ("I Want to Live!") to war stories ("Run Silent Run Deep") to Westerns ("Tribute to a Bad Man").

He also was nominated for an Oscar for editing "Citizen Kane."

"I'd rather do my own thing, which has been to choose projects that take me into all different kinds of genres," he once told The Associated Press. "I don't have a favorite kind of film to make. I just look for the best material I can find."

Wise died after falling ill and being rushed to the University of California, Los Angeles, Medical Center, family friend and longtime entertainment agent Lawrence Mirisch told The Associated Press.

The director had appeared to be in good health Saturday when he celebrated his 91st birthday with friends, Mirisch said.

Wise's wife, Millicent, learned of her husband's death while in Spain for the inauguration ceremony of the San Sebastian Film Festival, which was featuring a retrospective of his work.

While many of his films were classics of their genre, his two revered musicals towered over all of them.

Wise won the best director Oscar for 1961's "West Side Story" (shared with Jerome Robbins) and for 1965's "The Sound of Music." He also received producer Oscars for each film for winning best picture.

"West Side Story" was the tale of "Romeo and Juliet" set in the New York City tenement slums. Co-directed by Wise and Jerome Robbins, with music by Leonard Bernstein, it won 10 Academy Awards.

"The Sound of Music," which told the story of the singing von Trapp family's escape from Nazi-ruled Austria, won five Oscars. It was for many years the top-grossing film of all time.

Wise gave much of the credit for the film's success to its stars, Julie Andrews and Christopher Plummer.

"A big part of a director's job is done if he gets the right actors in the right roles," he once said. "That doesn't mean you don't help actors, but once we thought about Julie and Chris, we didn't seriously consider anyone else."

He also credited Welles, for whom he edited "The Magnificent Ambersons" as well as "Citizen Kane," as a major influence, adding that the actor-director-writer was "as close to a genius as anyone I have ever met."

"Citizen Kane" was "a marvelous film to work on — well-planned and well-shot," Wise once said. It has topped many polls over the years as the best film ever made.

More recently, he served as president of the Academy of Motion Picture Arts & Sciences and the Directors Guild of America.

Born Sept. 10, 1914, in Winchester, Ind., Wise dropped out of college during the Depression after his brother, an accountant at RKO, helped get him a job at the studio.

He worked his way up to film editor or co-editor on such movies as "The Story of Vernon and Irene Castle," "The Hunchback of Notre Dame" and "The Devil and Daniel Webster."

He got his chance at directing almost by accident when he was assigned to finish the 1944 film "The Curse of the Cat People" after the original director fell too far behind schedule.

Pleased with his work, horror film producer Val Lewton assigned Wise to direct the Boris Karloff film "The Body Snatcher" the following year.

In addition to his four Oscars, Wise was awarded the Academy of Motion Picture Arts and Sciences' Irving G. Thalberg Memorial Award, a special Oscar for sustained achievement, in 1966. He also received the Directors Guild of America's highest honor, the D.W. Griffith Award, in 1988.

His last film, 1989's "Rooftops," was another try at an urban musical like "West Side Story" but with modern-day pop music and rough language. It wasn't successful but many critics praised Wise's effort.