I listen to a pretty broad spectrum of stuff. (I recall a buy at a car boot not being able to get his head around it when I bought 2 albums from him. Cyndi Laupers True Colours and Metallicas Justice album. "But.. but.. "
I recall reading somewhere the first few beatles albums were original intend to be mono and the stereo version were an afterthought. Stereo wasnt a big thing when the first few were released which is why there were not many made. (The pressing plant was also in the process of switching labels from the black and gold to the black and yellow ones - which is why the black and gold ones are so rare)
Think there are also 2 versions of the black and gold ones - some have the wrong credits on there or something.