Setting the Focus on a Staff During Playback
During playback, Composer displays the measure and beat location of the score that is currently playing. If Composer's window is not tall enough to display all of the staves (staves) for the current measure, then Composer must decide which staves to display.
You can instruct Composer where to vertically scroll the window, according to which staff you want to keep in focus during playback. You may wish to do this while you are studying the role of a particular instrumental part or voice during playback.
You can assign the playback focus to a staff by setting the playback staff focus marker, as described in Playback Location and Staff Focus Markers. To set the focus on a staff either before playback starts or during playback, click the mouse anywhere in that staff while holding down the "V" (vertical) key.
If you scroll the window during playback, then the focus will shift to another staff, approximately in the middle of the window. Afterwards, that staff will remain in the same vertical position upon subsequent page turns.
If the Hide Resting Staves option is in effect, then the staff with the playback focus might temporarily drop out during playback, if there is no staff for the instrument. In this case, Composer attempts to find a nearby staff to temporarily assume the role of playback focus. As soon as the originally focused staff has notes, its staff will reappear, displayed in the same position as before.