TOEFL Listening: ETS-TOEFL听力机经 - D1S159TE411O_5Q4Q$

Lecture: Electronic music: Narrator: Listen to part of a lecture in a material science class. Professor: Probably the most important musical development of the 20th century was the emergence of electronic music, because the ability to generate sounds electronically opened up many new possibilities for composers. So let's look at three major breakthroughs in this area. The first was magnetic tape as a recording medium. Before magnetic tape, vinyl was used as a recording medium. There were vinyl record albums. Uh, maybe you've seen your parents' or grandparents' vinyl collections – those flat round, black this with the grooves. But in addition to being used for recording music take into a certain extent, vinyl could be used for creating music. Creating musical on tape was a vast improvement over vinyl, because tape is much more versatile. With vinyl, the only way sound could be manipulated was by changing the speed. But with tape sounds could be manipulated in many ways by cutting in splicing the tape. Um, let me give you an example of a type of music that employed these techniques. By the late 1940s, composers were experimenting with a musical style called music concrete. Music concrete began with natural sounds recorded on vinyl. But tape was even more conducive to creating music concrete. With magnetic tape, composers could cut the tape and splice the pieces back together anyway they wanted. Essentially reorganizing the sounds, they could add echoes or put in a piece of tape backward. Female Student: But what do you mean by natural sounds? I remember reading about some early composers using the sound of gravel moving in a box. Professor: Yes, that is probably the most interesting aspect of music. Concrete. Basically any sound, street noise, instrumental or otherwise recorded on tape could be manipulated into a music concrete composition. The only limitation was that composers' imagination, glass breaking industrial machinery, any sound was fair game. Now some critics don't consider these kinds of mechanical manipulations or even music concrete itself to be music. But I think that if you approach the material with an open mind, you'll realize what music concrete did was expand the definition of music and musical expression. Manipulating magnetic tape wasn't easy, though. It could take hours to produce one minute of music. Nevertheless, composers flock to this new medium. It became very popular and led to further experimentation and research electronic music. Now the next breakthrough was the synthesizer. Most of you have seen synthesizers and rock bands that keyboard player is almost always playing the synthesizer. It often looks like a piano. But does anyone know what the synthesizer really is? Male Student: It's an electronic instrument that mimics the sounds of a piano. Right? Professor: Okay. But the synthesizer is much more than an electronic piano, it's a machine. They can generate many types of sounds and that's a key point. Whereas tape machines could be used to manipulate sounds, they couldn't generate new ones. A synthesizer can generate new sounds and then combine them in infinite ways. You can imitate sounds of conventional instruments as well as create distinctive tones. And the second thing it can do is modified sounds. Male Student: Like changing the speed like you said before. Professor: Yes. And that's the beauty of a synthesizer. You can make sounds faster, slower, higher pitch, lower pitch. You can, of course, change the volume. You can make a single chord reverberate through an entire song, something the best musicians can't do with a conventional instrument. And all of this can be done, as you can imagine, relatively quickly, no more tape splicing. It's kind of like making furniture using modern power tools instead of hand tools. The difference is that dramatic. Ok, so moving onto the third innovation in electronic music. Can anyone guess? Female Student: Um, computers? Professor: Right. Many composers don't even use musical instruments anymore. As computers have become more powerful, many composers have taken to using software programs specifically designed for composing music. In a sense, the computer has become their instrument. This approach has many advantages. For example, one person can compose an entire symphony with thirty or forty or a hundred different instruments or sounds using sophisticated software, and then listen to it on the computer. And if they don't like what they hear, they can make whatever changes they want. Take out of melody here at another instrument there, speed up this section, make that section louder, and then play it again. More control, more artistic freedom. That's what these technological innovations have brought to music.