The CD, at 30, is feeling its age

Today the compact disc or CD turns 30. The disc has been declining in sales due to the convenience of digital music. NPR reports, this decline represents a long line of turn over for the industry, in roughly the same 30-year cycle. “Sam Brylawski, the former head of the recorded sound division at the Library of Congress, says, ‘If you look at the last 110-115 years, the major formats all have about 20 to 30 years of primacy.'” These formats include the phonograph, the 78, the LP, the cassette, and then finally the CD.