The Organ Reform Movement or Orgelbewegung (also called the Organ Revival Movement) was a mid-20th-century trend in pipe organ building, originating in Germany. The movement was most influential in the United States in the 1930s through 1970s, and began to wane in the 1980s. It arose with early interest in historical performance and was strongly influenced by Albert Schweitzer's championing of historical instruments by Gottfried Silbermann and others, as well as by Schweitzer's opinion that organs should be judged primarily by their ability to perform with clarity the polyphonic Baroque music of J. S. Bach (1685–1750). Concert organist E. Power Biggs was a leading popularizer of the movement in the United States, through his many recordings and radio broadcasts. The movement ultimately went beyond the "Neo-Baroque" copying of old instruments to endorse a new philosophy of organ building, "more Neo than Baroque".[1][2][3][4] The movement arose in response to perceived excesses of symphonic organ building, but eventually symphonic organs regained popularity after the reform movement generated excesses of its own.