Jeff Sessions' mix tape was called for.
  Although the compact audio cassette by Philips appeared at the 1963 Berlin Radio Show, the sound quality of cassettes was not good enough to be seriously considered for music recording until further advances in tape formulations, including the advent of chrome and metal tape
  The growth of the mixtape was also encouraged by improved quality and increased popularity of audio cassette players in car entertainment systems, and by the introduction of the Sony Walkman in 1979

