Voices and MIDI channels
Internally the program organizes the notes into voices by changing their MIDI channel values. Normally you set it up so that notes with MIDI channel 3 belong to voice 3 etc. Most of the time the link between MIDI channels and voices is totally transparent to you as a user. Sometimes you can take advantage of this relationship, as described later in this chapter.
There are also a few important things to note:
When you make a note part of a voice, you are in fact changing its MIDI channel value. However, when you change the voice’s MIDI channel values in the setup dialog, this does not affect the notes’ MIDI channel setting. This can lead to serious confusion, since the relationship between the notes and the voices is affected. It might even make notes disappear (the program warns if this happens). In other words, do not change the MIDI channels on the Polyphonic tab of the Staff page in the Score Settings dialog after you have put your notes into voices, unless you are absolutely sure of what you are doing.
When you open a part that contains notes on different MIDI channels, these notes are in fact already assigned to voices (since notes are assigned to voices using their MIDI channel setting). While this fact can be put to good use, it can also create confusion, and even disappearing notes, as described above.