In the final decades of the twentieth century we find numerous composers who base their music on extensions of the concept of tonality or pitch centricity, in styles that have often been called neotonal or neo-Romantic, in some cases featuring a clear revitalization of traditional tonality. This rediscovery of tonality and its expressive power in the late years of the century is patent in works by composers such as David Del Tredici, George Rochberg, Joan Tower, Wolfgang Rihm, Christopher Rouse, Aaron Jay Kernis, and Jennifer Higdon, or in recent works by Penderecki and Hans Werner Henze. Another powerful stylistic trend in recent decades, which we usually label as Minimalism, has featured the adoption of much simpler compositional means than most previous music in the twentieth century. Composers who have practiced the aesthetic of simplicity in one way or another include John Cage, Arvo Part, Louis Andriessen, Philip Glass, Steve Reich, John Adams, and Michael Torke.