Moses und Aron is an opera in two acts by the Austrian composer Arnold Schoenberg. He composed it to his own libretto (text), based on the biblical Book of Exodus (see Schoenberg, Arnold). Schoenberg wrote the whole libretto and the music for the first two acts between 1930 and 1932, but he did not complete the music for the third act. A concert performance of the first two acts was given in Hamburg, Germany, in 1954. It was first performed as a staged work in Zurich, Switzerland, on June 6, 1957.