I just spent the last few hours doing something quite interesting.
My dad had found two boxes in my grandmother's attic, as it was being cleaned out. He brought the boxes down, and discovered that they were full of my great-grandfather (who was an exceptionally good pianist, or so I am told), and great-great-grandfather's piano sheet music. So, I've been going through it (one box tonight, there is a lot in each box. Mostly theatre music, and dance music, i.e. march & two-step), and it is really fascinating. The oldest piece of music was published in 1888, and there was another in 1894, with the rest fitting into the periods 1900-1910, and 1930-1940. There were a few other ones as well, such as a World War One nationalist piece (published in 1915, complete with colourful front page artwork of soldiers) entitled 'Battle of the Nations, March Descriptive' by E.T.Paull.
Long rave, but it is really interesting. And quite well preserved, for the most part.