....First, it helps to get a clear idea of just how the new recording method differs from the old. In the past, all sound reproducers - from the tin- horn Victrola to the latest LP player - worked on the principle of analog recording. This means that the record groove is a replica of the actual sound wave. Fidelity depends on making the replica correspond precisely to the original, an ideal never fully attained. Besides, tracking a groove with a needle or stylus creates inherent distortions which, though greatly reduced in recent years, have not been wholly eliminated.
By contrast, the laser-scanned Compact Disk does away altogether with groove and stylus. Instead, every musical sound - as defined by pitch, loudness and timbre - is encoded as a binary number intelligible to computer circuits. These numbers - not the waveform of the sound - are recorded as a series of digital ''bits.'' (A bit, in computer lingo, is a basic unit of information, consisting of either ''1'' or ''0'' - that is, either the presence or the absence of an electric pulse.)...