Serialism is one of the most important post-war movements among the high modernist schools. Serialism, more specifically named "integral" or "compound" serialism, was led by composers such as Pierre Boulez, Bruno Maderna, Luigi Nono, and Karlheinz Stockhausen in Europe, and by Milton Babbitt, Donald Martino, Mario Davidovsky, and Charles Wuorinen in the United States. Some of their compositions use an ordered set or several such sets, which may be the basis for the whole composition, while others use "unordered" sets. The term is also often used for dodecaphony, or twelve-tone technique, which is alternatively regarded as the model for integral serialism.