It's basic economics: things that are hard to get are more valuable. Another factor is the ubiquity of music - it's in grocery stores, in advertisments, everywhere. I wish I could have the experience that people had before gramaphones - not having heard music for months and then going to a concert. It must have been mind-blowing.
You may be underestimating the amount of music that was around: people had pianos, people had guitars and banjos, there were amateur bands and choral societies, many went to churches with fair to better choirs, etc.
Although I do agree with that generally, but there was an effort involved. You had to plan ahead, usually it might be done kind of a social occasion, or you had other chores to fulfill of you yourself knew how to plan an instrument.
Today, it's available with just a press of a button, and I think that's the main point of the article.
