Flat disks made of a petroleum-based plastic called vinyl were the preferred media for popular music reproduction before the advent of magnetic tape and digital CD technologies. Vinyl records supplanted an even older wax-based cylinder system that served as both a recording and playback device. Portable turntables known as Victrolas and ornately decorated record players had largely replaced cylinder players in most homes the 1920s. Vinyl was discovered to be more durable and easier to store than wax.
Vinyl records are created after a lengthy recording session. The performers gather in a special room designed to block out background noise. An electronic microphone picks up vibrations from their voices or instruments. A wax disk spins at a set speed as these vibrations are received. Originally, a ten-inch disk rotated at 78 revolutions per minute, but the music industry later adopted a 33 rpm speed for 12 inch (30 cm) disks and a 45 rpm speed for 7 inch (18 cm) disks, commonly referred to as singles. Some spoken word albums do spin at 16 rpm, but these are uncommon.
A sharp needle carves a groove from the outside edge to the inside of the wax disk at a constant speed. This needle vibrates as it moves due to the vibrations from the recording session, recreating the sound waves of the original voices or instruments. This wax disk serves as a template for a metal master disk. The master disk is then melted and injected into the machine with the vinyl plastic. The groove is precisely recreated as the metal disk is pressed into the pliable vinyl. The vibration pattern in the groove is picked up the needle on a record player, and the sound is amplified for the listener an electronic amplifier. Even if a player is turned off, the needle and record can still produce sound.
Other than storage and reproduction, vinyl records became popular. Musicians discovered that the vinyl covers and sleeves could be used for artistic purposes as well. Songs could be collected on albums, which are 12 inch (30 cm) disks, or EPs, which are smaller collections of songs. Single 45 rpm disks could be used to market popular songs from albums.
Regrettably, vinyl records’ fragile nature proved to be their commercial undoing. During the 1970s, cassette tapes made of durable magnetic tape grew in popularity, followed the revolutionary digital technology of the CD or compact disc. Vinyl records are still manufactured in small quantities for amateur musicians on a budget or performance artists who scratch vinyl records. Many people enjoy collecting vinyl records because they prefer the organic sound of a record to the sterile but more perfect sound quality of a CD.