Mad About MIDI
MIDI files are a real throwback to an earlier era, when passing around Mbytes of data was not an option. Sleek MIDI files - typically a few tens of kilobytes - were perfect, even if the sound quality left something to be desired.
I thought that MIDI had pretty much disappeared, but on the contrary, it seems to be thriving. Take Kunst der Fuge, which has a huge collection of classical music, although not all of it freely available.
And it's not just the obvious stuff. Here, for example is pretty everything that the insane but amazing French composer Charles Valentin Alkan wrote. Since much of it is almost unplayable by mere mortals, MIDI files are probably a good way to hear the stuff. (Via Creative Commons.)