Otto Friedrich -- pianist, historian, adventurer, rose gardener and passionate journalist -- was above all a man who had to write. In addition to his prodigious work during two decades as a writer and editor at TIME, Otto wrote 14 books on subjects ranging from Berlin in the 1920s to Hollywood in the 1940s to the End of the World-to say nothing of the nine children's books he co-authored with his wife Priscilla, with whom he had five children of his own. When Otto died of cancer last week at age 66, he had just completed a monumental study of the military Von Moltke family of Prussia and Germany and was hard at work on a book about the Victorian age.

A tall, self-effacing man with a boyish grin, Otto arrived at the office each day carrying his lunch in a brown paper bag. He left at precisely 6 p.m. to catch the train to his home on New York's Long Island, where he worked mornings and weekends at his 27-year-old Royal 440 manual typewriter, turning out books at the rate of two pages a day. (He once broke off in mid-sentence after reaching that quota.) Otto's contributions to Time went beyond his muscular prose. A patient, sometimes acerbic and always inspiring mentor, Otto set standards of excellence for the magazine. "If you're lucky," says senior editor Nancy Gibbs, "you find one teacher like that in a lifetime." When a correspondent's interviews with celebrities from Madonna to Steven Spielberg caught his eye, Otto showed the pieces to publishers until one bought them for a book.

Always a lightning-fast study, Otto graduated from Harvard at 19. He was managing editor of the Saturday Evening Post when that weekly folded in 1969, and chronicled its death throes in an acclaimed book called Decline and Fall. He joined Time in 1971, where he supervised historical projects like our 1976 Bicentennial issue and wrote 40 cover stories, including one that named the personal computer as Man of the Year, before retiring in 1992.

Otto found writing ideas everywhere. His fondness for roses blossomed into a book about the joys of that flower. His love for the piano led to a biography of pianist Glenn Gould. For years, Otto and former senior editor Ruth Brine, a skilled violinist, met regularly during the lunch hour to play duets. "We had three-sonata lunches," Brine recalls. She once dreamed that the sessions had exhausted all the music in the world, but Otto reassured her that that could never be the case. For Otto Alva Friedrich, there was always another sonata to play, another rose to cultivate, another book to write.