Norio Ohga was a japanese businessman that climbed up the ladder until he became the CEO of Sony. In 1982, when they were deciding the specifications for the Compact Disk, he insisted that the CD should be 12 centimeters in diameter.
At 12 centimeters, the CD would be able to hold 75 minutes of music. Norio Ohga's reason for this is that he wanted a CD to be able to hold Beethoven's 9th in full. Ohga also predicted that CDs would soon replace record sales. It only took 5 years for his prediction to come true.