Excerpts from Books and Wikipedia
"Caruso, born in Naples in 1875, was the outstanding tenor of his time and for 17 years was the principal tenor of the Metropolitan Opera House in New York. . . . Emile Berliner developed a system of recording onto a gramophone disc, which had many advantages over the cylinder and the phonograph. Although the recording quality was no better, it was easier to make multiple copies through molding and pressing. The gramophone also needed less adjustment and could carry a recording on both sides of the disc. All of Caruso's 450-plus recordings were made for it, and it became the most desirable and popular domestic entertainment system in the first half of the century." [Furtado: 1001 Days] "A gramophone record (phonograph record in American English) or vinyl record, commonly known as a record, is an analogue sound storage medium in the form of a flat polyvinyl chloride (previously shellac) disc with an inscribed, modulated spiral groove." [Wikipedia]