Too bad it's probably just images embedded into the pages though. It'd be really cool to turn the speech-to-text feature (on silent) and use it to run through the notes line per line while playing.
I wouldn't say the Fire worked well for something like that though, the DX is a little better but most of the sheet music I have is much larger than 8x11.
But thanks, now you've gave me the idea to go and convert my stuff for the Kindle.