It might be fun/interesting to pipe pieces transcribed to MIDI into your system and see what falls out. I'm sure it'll be nonsense, but perhaps fun nonetheless. (e.g. http://www.piano-midi.de/chopin.htm)
I made a little explanatory document (https://goo.gl/Vq3Fsb) to go along with the typing tests that I streamed today, and that was one of the things that I mentioned (copy/pasting from there):
Q: Can you play a real song so that we can see what it types out?
A: This isn't as satisfying as you may think since the entire typing range is only about two octaves, and most songs exceed that range, so nothing actually gets typed when you play those notes. Anyway, here's Wonderwall: Iuiuigaezobzgbxgebiuiuigaezobzgbegz
Q: Can you play a real song so that we can see what it types out?
A: This isn't as satisfying as you may think since the entire typing range is only about two octaves, and most songs exceed that range, so nothing actually gets typed when you play those notes. Anyway, here's Wonderwall: Iuiuigaezobzgbxgebiuiuigaezobzgbegz
(that's actually the right hand of Für Elise)