A friend (who has unfortunately passed away) owned, together with his father, just about every opera CD ever made (his father worked in RAI (Radiotelevisione Italiana) and was also an opera fanatic). So, in order to get more opera he used to go to opera performances and record them. When the season opened he would go regularly to e.g. La Scala in Milan, and record the performances. That wasn't actually allowed, but the people there knew him and they knew why he did it (for personal use only), and let him in. To be at the best recording place he would have to get a seat in a section which required that he wore a suit, so he would often wear a smoking - which he actually hated, but he could put a microphone on each collar and get a stereo recording. In the nineties he used a DAT recorder.