Once upon a time not that long ago, all music was expected to sound clean and clear. Pure, accurate, right in tune. And lo, it was…fine.  But with the introduction of the electric guitar and the amplifiers that went with them, some intrepid players started experimenting with ways to toughen up that sound. They wanted more power, more growl, more rawness. And over a period of about 20 years, the clean, pure sound of the original electric guitars gave way to something dirty, distorted, filled with harmonics, and various amounts of feedback and noise.  What was once considered undesirable, irritating, excruciating noise is now looked upon as beauty.  Learn more about your ad choices. Visit megaphone.fm/adchoices