I understand it is a new feature. MIDI is a programming language that can be used for many things besides triggering sounds.

However, even before when you entered chords or imported a *.sgu or *.mgu file with midi data ... that data still must have been the front end 'trigger' to cause the compiling of the RealTracks. There's not a little man in the program who goes and gathers the data after each chord you enter.

If you look at the midi in the track at about 11:40 in the video you see that it looks like it's showing a lot more midi note data than simply chords you'd see in a chart.

There also seems to be notation windows that follow the RealTrack with the blinking red notes ... or in the fret board you can see double stops. That looks like a lot more than a chart.

Prado