The Mine Foreman (German: Der Obersteiger) is an operetta composed by Carl Zeller with a libretto by Ludwig Held and Moritz West. It premiered on 5 January 1894 at the Theater an der Wien in Vienna. In 1952 the libretto served as the basis for a film The Mine Foreman. The operetta is rarely performed today, but the aria âÂÂSei nicht bösâ (âÂÂDonâÂÂt be crossâÂÂ) has become a concert staple.