Sony's Walkman Turns 40 Years Old

PHILADELPHIA (CBS) -- In July of 1979, Sony revolutionized the way we listen to music. That is when the company released the portable cassette player, called the Walkman.

For the first time, listeners were able to enjoy their music privately through headphones.

At its release, the Walkman cost $150 and became a blockbuster hit, selling 50,000 devices in the first two months.

However, in 2001 sales began to drop when Apple unveiled the iPod and digital downloads began to its ascent.