New technologies bring with them new sonic phenomena all the time. Cage was autely aware of this and embraced it as a perquisite of progress (and later changed his mind a bit on the issue, but we'll overlook that for right now). I was thinking about this the other day and decided that one such technology that has undoubtedly brought with it its own "soundtrack," as it were, is the telephone. With all man-created sounds, the telephone has introduced noises into popular culture that today are universally recognized. The dial tone, the busy signal, various recognizable rings, even the "low battery" sound on many cell phones has become largely self-evident. It's amazing how these sounds have become so ingrained into our upbringing in this country that their identification is now second nature.