Known to friends and colleagues as "Jamie," Mr. Hammerstein was responsible for inviting a neighbor friend named Stephen Sondheim into the Hammerstein home. The future composer- lyricist Sondheim became a longtime family friend, but, more importantly, was a student and protégé of Oscar's. Immeasurably influenced by Hammerstein, Sondheim went on to bend rules Oscar had established for the musical stage.