A week before his 100th birthday, George Abbott rests quietly in his Algonquin Hotel suite, hours after rehearsing the revival of his 1926 play, Broadway. With a steady hand he slips a hearing aid into his right ear, cocks his head as the whir and blare of Manhattan traffic filters up from the streets below and says it's practically like old times. "Maybe it's fitting that the biggest hit of my career, my first big one, is now my last," he muses. "I guess I'm coming full circle." His gaze moves past his wife, Joy, 55, to a collection of playbills announcing a few of the 128 shows he's been involved with, as actor, director, writer or producer. "But I've still got some more ideas, more plays I want to do," he says with an impish smile. "I can't tell you what they're about. That would be foolish."

Mr. Abbott, as all but his closest friends call him, never appears foolish. He has, in fact, defined himself diametrically otherwise—as an austere, blunt-spoken taskmaster, the Great White Way's equivalent of a Marine drill instructor. Abbott took the moribund, convention-bound Broadway musical, gave it the staccato, bang-bang rhythm of contemporary street life, and in the process became one of the great shaping forces in American theater history. Pal Joey (1940), Call Me Madam (1950), The Pajama Game (1954), Damn Yankees (1955), A Funny Thing Happened on the Way to the Forum(1962)—the list of shows with the Abbott stamp is decades long. So is the roster call of talent he has helped squire into showbiz: Gene Kelly, Shirley MacLaine, Kirk Douglas, Van Johnson, Richard Widmark, Carol Channing, Hal Prince. As choreographer Jerome Robbins, another protégé, says, "George is Broadway's longest-running hit." Yet Abbott is still looking ahead to the next show, still seeking the unknown hopefuls waiting in the wings. "Never look back," says the wiry, 6'2", straight-backed master. "My legs may be gone, but my brain isn't. I still like young people who are excited and eager."

Born June 25, 1887 in Forestville, N.Y., Abbott grew up in western New York, Wyoming and then Nebraska, where his father sent him to military school. Abbott has always believed that the most important legacy he received from his father—a government land agent with a drinking problem—was a love of exercise and a lifelong aversion to liquor and cigarettes. He took his professional instruction from George Baker, the innovative playwriting professor at Harvard, where Abbott enrolled in 1911. It was from Baker, who was also Eugene O'Neill's mentor, that Abbott learned the importance of the quick-pulse pacing that later became his trademark. Broadway acknowledged it in his first big hit, Broadway. Coauthored with Phillip Dunning, the play captured the helter-skelter tempo of the Roaring Twenties, a time of speakeasies and wise-guy gangster slang. "I sat in the audience opening night watching to see if people were reading their programs," Abbott recalls. "When they do that, you know they're bored. That night no one was reading programs."

There were no such certainties to inform his life offstage. Abbott's first wife, teacher Ednah Levis, whom he had wed in 1914, died of cancer in 1930. His second marriage, to actress Mary Sinclair in 1946, ended in divorce five years later. In a sense Abbott's most devoted family was composed of the people he worked with. Although he didn't hesitate to show his impatience with method acting and prima donna behavior, he won worshipful respect for his calm and unerring direction. "I'm frank with actors, always careful not to hurt them," he explains. "They give their best when they're comfortable."

Married to Joy Valderrama, a furrier, since November 1983, Abbott divides his time between homes in Miami Beach and New York's Catskill mountains. He has descended into Manhattan expressly for Broadway. "I think I'm as excited as I was in 1926," he says. "It's the same play, but you never lose that anxiety. I'll still be in the audience watching—to see if people are reading their programs."