You left out the 8-tracks. Before cassettes were used for music in the US they and their tape recorders were a rare import, just a slick portable tape recorder

You left out the 8-tracks. Before cassettes were used for music in the US they and their tape recorders were a rare import, just a slick portable tape recorder like the portable battery-powered mini-reel-to-reels which were just using small reels of full-size 0.25 inch tape (you still had to thread them yourself). But too expensive for casual or student use, these were the newest exotic office machine for dictation, monophonic only of course like the little reel-to-reels. For music in the car the 8-track tape cartridge was well established and growing wildly, with its single endless reel of the regular 0.25 inch tape inside, but having multiple _tracks_ so you could get stereo and more music on less tape. I was so fortunate my father got the first portable Sony cassette recorder for his business, there was only one specialty store that had unique imports like that. He eventually let me bring it to school instead of my little reel unit one day, this was about a year before any pre-recorded music tapes were available. I was recording off the radio, AM of course since pop music had not yet made it to FM and the FM sets and broadcasting stations, though not many were very powerful or stereo yet, basically had an insignificant fraction of listenership compared to AM. Remember Woodstock came out on stereo LP's, 8-tracks and cassettes, but on the radio (which is about the only way stuff got popular) almost everyone was listening to things in monophonic for years to come. This was before FM stereo pop stations began to prevail, followed by home consoles and AM/FM car stereos. Only 5 years before Woodstock, most people were still buying mono vinyl since stereo cost extra and few had stereo players. By 1969 mono vinyl was not for any major releases. Even after FM stereo took over at home, most second-hand cars only had mono AM radios left over from just a few years earlier, but did slowly get replaced by newer vehicles. But FM still cost extra for years to come so plenty of cars were still shipped with the tradtitonal stock AM radio only. Music lovers who wanted no commercials all had 8-tracks already. Nothing in-dash was found, still under-dash like a CB radio. Anyway, at school it was still the point where no other businessmen, teachers, or students had seen anything like a cassette, so it was a curiosity but not completely unexpected due to such great familiarity with other dictating machines and 8-tracks too. People thought the tape was cool since it was smaller, easy to use, and worked like a tiny reel-to-reel, plus we naturally had a lot of fun recording with the microphone. 8-tracks didn't record for years to come. By the end of the day when one of the umpteenth students to be amazed at my little recorder saw it I just naturally blurted out, "It's going to replace the 8-track". Of course everyone laughed since there were no music tapes from record companies and no stereo. But you could record your own, and the rest is history. Eventually one day my father got me a Beatle tape from Capitol records, Sergeant Pepper was the only one made at the time. Inside the little fold-out tape liner they had the entire catalog of Capitol cassettes listed, these were stereo but played perfectly on our mono player too. All 6 titles, one Beatles, one classical, one Sinatra, one jazz, and a couple soft pop. Capitol was just testing the waters. Eventually got one of the earliest Ampex home cassette decks, naturally with sliders to mix stereo mics together with stereo line inputs. Then Ampex got kicked out of the consumer market on a technicality where they had supplied a non-updated schematic with a product after a single component had been changed. By 1973, Sony had just come out with their first stereo portable cassette recorder, same size as my early mono unit but with an additional matching auxillary speaker. Also their first single hand-held stereo directional microphone, which my buddy's father had gotten for him these years later. They were expensive. And they had just invented Memorex tape, before that you could not record a live rock concert very well. We had always tried to keep up with an interesting group of English artists who had been coming to town for 5 years beforehand, they were too different to be on the radio yet, but since the first time I saw them people had been telling me I was crazy when they heard it. "Nobody's ever going to listen to that, these guys are never going to be on the radio." Anyway, when Pink Floyd came to town this time they had just released a little record called The Dark Side of the Moon, which was Quadrophonic in concert and also available quad on vinyl. Each year they always played a set of the earlier material, then took a long break and came back to play their new stuff, usually no opening acts. It was crowded for the first time, mainly with new fans who were very anxious for what they had heard on the radio, but there was none of that and then the band took a long break as usual. It was almost like a riot but once they got back on stage and played the whole Dark Side everyone loved it and they've been on the radio ever since. Got it all on tape. In stereo. Quad didn't really catch on. On the way back from the concert we listened to it on my Sears car cassette recorder (with mic unplugged!), underdash of course, the first one they had in the catalog.