More than a century ago, the composer and bandleader John Philip Sousa warned that technology would destroy music, who said, "These talking machines are going to ruin the artistic development of music in this country. When I was a boy ... in front of every house in the summer evenings you would find young people together singing the songs of the day or the old songs. Today you hear these terrible machines going night and day. We will not have a vocal cord   left." Music has greatly changed in the past hundred years, which has been everywhere in our world: rivers of digital melody flow on the Internet or on disc; MP3 players with forty thousand songs can be put in a back pocket or a purse. Yet, for most of us, music is no longer something we do ourselves, or even watch other people do in front of us. It has become a radically virtual medium, an art without a face. Ever since Edison invented the phonograph cylinder , people have been assessing what the medium of recording has done for and to the art of music. Sousa was a spokesman for the party of doom; in the opposite corner are the utopians , who argue that technology has not imprisoned music but liberated it. Before Edison came along, Beethoven's symphonies could be heard only in select concert halls. Now the recordings carry the man from Bonn to the corners of the earth. Glenn Gould, after renouncing live performance in 1964, predicted that within the century the public concert would disappear into the electronic air. Having discovered much of my favorite music through LPs and CDs, I am not about to join Sousa's party. Modern urban environments are often so soulless or ugly that I'm grateful for the humanizing touch of electronic sound. But neither can I accept Gould's slashing futurism. I want to be aware of technology's effects, positive and negative. Fortunately, scholars and critics have been methodically exploring this _ for many decades, trying to figure out exactly what happens when we listen to music with no musicians in the room. The primary purpose of the passage is to  _  .
explain different attitudes of scholars and critics defend the view of one group from the criticism of another advocate an unexpected solution to a pressing problem present the key issues in an ongoing debate