to keep cinemas well stocked with films,Hollywood had perfected an efficient form of mass production. Studios were organized by departments, such as screen-writing, editing,and sound,all headed by a production chief who oversaw operations. The major studios turned out two types of pictures:class a, with big-name stars and big budgets,and class b,economy films.to maintrain audience interest ,studios produced a range of genres,including musicals, comedies, and westerns.And to satisfy motion picture censors, the industry adopted the Motion Picture Production Code in 1930,whereby producers voluntarily agreed to make their film content follow a generally accepted code.