Johann Andreas Stein, German piano builder (b. 1728)
Johann (Georg) Andreas Stein (16 May 1728 in Heidelsheim – 29 February 1792 in Augsburg), was an outstanding German maker of keyboard instruments, a central figure in the history of the piano. He was primarily responsible for the design of the so-called German hammer action. Pianos with this hammer action, or its more developed form known as the Viennese action, may be said to be appropriate for the performance of the piano music of Haydn, Mozart, and the early Beethoven.