Phillips invented the "Compact Cassette" in 1963 and the first machines appeared around '64 but were mostly voice grade for dictation. The first pre-recorded stereo music cassettes came out in '65. I still have a Jerry Lewis and the Playboys one from then. They weren't considered really hi-fi until the Advent 200 came out with Dolby B in 1970. (the wiki btw wrongly says the Advent 201 was the first with Dolby in 1971). I still have have my Advent 200 (and 201) that I bought new. It was a big deal when it came out and they used to do demos comparing its sound quality to that of reel to reel machines. Useless trivia = Nakamichi got their start making transports for the Advent 200 and other early cassette decks built by/for other companies.
Dave
