Optical disc composed of a phase change material, most often AgInSbTe, an alloy of silver, indium, antimony, and tellurium. Optical discs are most commonly used for storing music (e.g. for use in a CD player), video (e.g. for use in a Blu-ray player), or data and programs for personal computers (PC). The Optical Storage Technology Association (OSTA) promotes standardized optical storage formats. Although optical discs are more durable than earlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact optical media preservation procedures to ensure continued usability in the computer's optical disc drive or
Picture disc picture disc is "To Elvis: Love Still Burning", a collection of 11 Elvis Presley tribute songs by various artists, issued in May 1978. Both sides of the album (Fotoplay FSP-1001) picture Presley. On some picture discs, the images used were meant to create an optical illusion while the record was rotating on the turntable (as in the B side of Curved Air's "Airconditioning"), while others used the visual effect to add to the music — for example, the 1979 picture disc of Fischer-Z's "The Worker" featured a train which endlessly commuted around the turntable, reinforcing the song's message. Later picture