MUSIC CD'S.

CD's were developed to have one or more stereo tracks stored using a 16- bit P C M coding and a sampling rate of 44.1 KHZ In size the standard disc is either 80 MM or 120 mm in diameter. the larger and more common CD can store 80 minutes of audio while the 80 mm holds about 20 minutes.

As early as the 1970's Philip's developed Laser Vision discs. In 1979 Philip's an Sony joined up to try to produce a new digital audio disc. The CD was invented collectively by a large team. It first reached the Asian markets and then was distributed throughout the world.

Polygram mass produced the first audio CD in Hanover, Germany in 1982 recording the classical music of Chopin's waltzes played by pianist, Claudio Arrau. The first pop CD was Abba's album, The Visitors.

The design of the CD was first an evolutionary process from the gramophone record. Later in 1985 the CD ROM (read only memory) was introduced and by 1990 the CD Recordable disc was introduced, both developed by Sony and Philip's.

Compact discs are made from a 1.2 mm thick disc of pure polycarbonate plastic to which a thin layer of Super Purity Aluminium is applied and in some rare limited edition CD's a layer of gold. lacquer can be printed with a label. most printing is achieved by Silk Screening and offset printing.

Data is stored in tiny indentations called pits. These pits are 100 mm deep by 500 mm wide and up to 3.5 mm in length. The CD is read by focusing a 780 mm wavelength semi conductor laser through the bottom of the polycarbonate layer. The Red Book originally developed by Sony and Philip's determines the specifications for a CD

If you think CD's are big business you're certainly right. The known sales amount to more than 30 billion worldwide per year. Sales are worth hundred's of billions of dollars. No wonder pirating is such a racket!

You will find some very beautiful CD music for your pleasure and enjoyment.