Life Begins at Twenty.(anniversary of compact disc)

The compact disc celebrates a birthday

Late in 1981, I was among a group of technical reporters who had been invited to Japan, but I was given no due about the purpose of the trip. As we trudged through Sony's laboratories in the Shinagawa district of Tokyo, we soon sensed that this was no ordinary factory tour. A feeling of impending surprise, of gleeful anticipation hung in the air.

Finally we were seated in a small auditorium. Grieg's Piano Concerto filled the hall with exemplary clarity. We were sure we were hearing a pristine master tape, just off the studio recorder. But at the end of the first movement, Akio Morita, the chairman of Sony Corporation, pulled a small silver disc from the player and announced triumphantly, "You have been listening to this!"

We were dumbstruck. Our amazement seems odd today, when microstorage devices for digital data -- and that is basically what a CD represents -- are commonplace. But back in 1981, the very idea of transforming music into digital data seemed stupendous. We sensed a watershed separating two eras of recorded sound -- analog and digital. It signified a totally new aspect of the entwined relations between music and mathematics.

Another striking departure from tradition was the unusual development history of the CD. It arose not from industrial competition but from a rare instance of cooperation between rivals. Sony had conceived the CD as a marriage between the phonograph and the computer, devising the mathematics and the chips to translate musical sounds into digital bits. But it was Sony's rival, Philips of the Netherlands, that obligingly provided the missing link: a way to etch those bits on a metallic disc with a laser beam, then play back the disc by scanning it with another laser beam. In fact, the CD represents the first domestic use of laser technology. Together, Philips and Sony thus laid the groundwork for the first departure in principle from Edison's "talking machine," invented a century before.

Edison's method was that of analog recording: the actual sound waves were cut into the record groove as tiny wiggles. This approach endured over a hundred years. Even in tape recording (invented in Germany during the 1930s), the analog principle was followed, with the magnetic patterns on the tape spelling out the shape of the sound waves. In essence, the wiggly groove or the magnetized ribbon carried an actual image of the musical sound. Consequently, the method could be visualized and understood intuitively.

Not so with digital. The notion of chopping Beethoven into numerical bits somehow goes against the grain. We perceive the flow of music as continuous. It is hard to envision a Schubert quartet as a set of numbers etched by a laser into a disc in the form of tiny pits.