I read this rather interesting BBC article on destroying pianos the other day: BBC News - Will your piano end up in the dump? It was fantastic to read something in the mainstream national media dealing with the sociological aspects of music history, as it is so often swept under the carpet and ignored.
The huge demand for pianos at the turn of the twentieth century is a significant point in the history of amateur music making, which goes back to the second half of the eighteenth century, when pianos were first manufactured in London. I've been doing some reading on this recently for my Keyboard Sonata essays, and it's fascinating how many aspects of our current musical culture can be traced back to some key developments around 250 years ago, such as the beginnings of public concerts, the development of the musical canon, and the appearance of a divide between popular and classical music.
The current move to digital music consumption and production is the next big shift in our musical culture, and it will be interesting to see how this plays out in the next few years. I suspect that it will be rather less than 100 years before today's digital keyboards become obsolete.