Q: Where can I download a good version of this? A: If you sign up for a Vimeo account (free), you can download the .m4v (QuickTime) original of this (the one I uploaded to YouTube); this can be played on your computer, or a video iPod; here's the link: http://www.vimeo.com/204519
Q: What instrument is that? A: The instrument here is a Post fortepiano (a sampled instrument), used as a pedal piano.
Q: Who is performing? A: This rendition isn’t exactly a performance in the traditional sense; it was done by Stephen Malinowski (smalin, me) using the conductor program; you can read more about that here: http://www.musanim.com/tapper/
Q: What do the colors in the bar-graph score mean? A: The colors show which "voice" is playing.
Q: Why are there two lines an octave apart in the bass? A: In organ music, the parts are often doubled with pitches that are higher than the notated pitch. In addition, the lowest part, played by the pedals, is sometimes doubled an octave lower. When parts are doubled, you tend to hear the lowest pitch, so in the bass part, there was the question: should I show the notated pitch or the pitch you hear? I decided to show both.
Q: Is there a way I could make the bar-graph scores myself? A: The Music Animation Machine MIDI file player will generate this display; you can get the (Windows) software here: http://www.musanim.com/player/ There are lots of places on the web where you can get MIDI files; I usually go to the Classical Archives site first: http://www.classicalarchives.com/