The second half of the 20th century was void of a dominant style in music composition. The aftermath of WWII, the advances in terms of recording and information technology, and the global political and economic context all played a role in the rise of new artistic and musical movements. Indeterminacy and chance (which had been championed by Charles Ives) rose as techniques and were adapted by the so-called New York School (John Cage, Christian Wolff, Morton Feldman). Electronic music and musique concreté redifined the potential of every sound as musical material. Minimalism challenged the narrative characterization of music, and, in general terms, most of the trends questioned, at one point of other, the traditional definitions of 'composer', 'performer', 'audience', etc. Popular and academic music influenced each other like never before in history, and the line between them became undefinable in some cases.