Radio is a profoundly powerful medium for mass communication. True, it is extremely limited in its range of transmission; neither colors nor shapes can be shared. But this very restriction compels both speaker and listener to concentrate on the message and the words used to express it. Like books, radio seeks to engage us primarily with the most powerful imagery of all, that of language. Whoever said "a picture is worth a thousand words" obviously missed a central portion of the human experience. The images radio generates are internal to us and are far more meaningful than a screen of brightly colored pixels.

Radios, like typewriters, are a holdover technology from a past age; they seem almost archaic in a world of CDs and personal computers. When filling out a form with a typewriter, I marvel at the precision with which I can direct letters onto the page, the feel of the keys, the instantaneous response of the machine. While the radio is similarly familiar and comfortable, unlike the typewriter, it retains an influential role in our world. It shapes our lives with its music, with its ability to surmount our visually based prejudices, its openness to listener input, and its power to change the way people think.

Radio remains pervasive, in part, because it engages our intellects while leaving our eyes and hands free to govern other tasks. We can absorb ourselves in comedy as we drive, listen to soft background music as we do our work, or follow a football game while doing household chores. Radio introduces new ideas or thoughts to us while we are still interacting with the world around us; the artificial boundary between reality and fantasy which exists in visual media is obscured.

Those musicians past whose primary ambition was to be played on the radio had to write resonant music and powerful lyrics to succeed. Many musicians today seem unenthused about their melodies and lyrics; they have become visual and dramatic artists, hoping to impress audiences with flashy music videos. Roosevelt's fireside chats and Churchill's wartime broadcasts focused the attention of their listeners, moving them in a way that a televised speech�with its visual images distracting from their words and intonation�would have been hard pressed to match. People responded emotionally to radio shows, from the War of the Worlds to Jack Benny's performances, in a way that few of us respond to media today. A radio broadcaster's clothes, race, and haircut are wholly invisible. The speaker, engaging the audience with the power of language and voice alone, is able to influence his or her audience with the barriers of prejudice minimized.

The opportunity to call in and speak on radio shows opens our ears to one another's views. Public debate of issues is a hallmark of many radio shows, and the price of participation is only that of a local phone call. During the 1992 American election, candidates promulgated the virtues of an Internet-based "electronic town hall," though a radio-based version has existed for much of this century. Exciting as the Internet is as a forum for discussion and debate, it is accessible only to those who own expensive computer systems. By contrast, a radio can be purchased for the price of a couple of boxes of cereal, and can be built by an enterprising hobbyist even more inexpensively.

Constructing a radio is not only an activity of hobbyists, but also of those in dictatorships who wish to clandestinely hear forbidden broadcasts. Invisible electromagnetic signals penetrate the most tightly guarded frontiers, piercing the information monopolies of illiberal regimes. Throughout the Cold War, institutions such as Radio Free Europe, the Voice of America, and the BBC sustained the strength of those who dared to dream of freedom. They informed millions of people of the liberties and opportunities available beyond the Wall and the Curtain. Though it may seem idealistic, I staunchly maintain that truth is the greatest single weapon in the arsenal of democracy, and it can be transmitted more widely by radio than by any other medium. Anyone who doubts the importance of information in resisting tyranny should take note of the lengths to which authoritarians go in trying to jam international broadcasts. Even in those societies most resistant to change, radio has the power to transform political and social orders.

Through the magic of shortwave radio, one can hear broadcasts from all parts of the world. Personally, I listen to the BBC news to gain an international perspective on the world news, and practice languages by listening to Colombian music and Japanese news programs. The truly global nature of shortwave radio does a great deal to bring common experiences to people in disparate parts of the planet.

But the localism of most radio stations is also an asset; it helps to give different areas distinct characters. In the course of traveling, one is immediately struck by the diversity of radio stations which offer us, free of charge, a kaleidoscope of sounds and thoughts. With such a wealth of options, the choice of one's favorite radio stations is an intensely personal one.

No matter how carefully one selects a radio station, though, the medium is still quite unpredictable, rapidly shifting between different songs and subjects. Through it, we hear music and new ideas that we would not have sought out consciously. Though we lose some of the control that we have in listening to a tape or CD, this element of randomness helps to make radio a broadening experience.

This century has been one of revolutionary advances in communications technologies. The advent of the telephone has enabled us to maintain far better contact with one another. Movies--the better ones, anyway--have made us laugh, cry, and think. Television, despite its tremendous contributions to illiteracy (and, indirectly, to heart disease), has altered the way we look at the world; its images have dramatically shaped every aspect of our lives, from our conversations to our wars. At the present time, the advent of worldwide, nearly instantaneous, nearly free communication via the World Wide Web is literally changing everything.

Still, in an age of ever more complex technologies, it is often the unassuming, seemingly antiquated ones which retain the greatest impact upon our lives. Such a device is the radio, whose near- century of existence has dimmed little of its luster. It has aged well, and promises to continue to serve us for many generations to come.