The CD was designed in such a way that he could play Beethoven's Ninth Symphony

Norio Ohga - Japanese businessman, who rose through the ranks to the post of Director General of Sony. In 1982, when it was discussed, what qualities will have a new - CD Ohga insisted that the size of the CD has been such that it placed the entire Beethoven's Ninth Symphony. It was decided to make a disc of 12 cm in diameter: at this size it can record 75 minutes of music, and Og the requirement has been satisfied.

via factroom.ru