4 track it was never that popular "at least not like the 8 track" and Sony mini CD wish in many way is superior to the standard size CD "smaller and protected inside from scrathes and smudges .
I remember qudraphonic music systems in the 1970's.Trouble is that we have two ears , not four. Eight track cartridges ( known as 8TC) were a type of audio cassette that were around in the early 1970's. Although technically superior to cassettes they only had limited success. In the mid 1980's in Australia, canned fruit that had the contents suspended in jelly instead of syrup or juice could be found on supermarket shelves. To remove from the can, you had to open both ends and push it out.