The Extend Isolated Notes display option is set by default to Yes. In this
case, all notes will extend in duration to the beginning of the next note, 
or to the beginning of the next beat, whichever is first.  This makes notes
appear longer than they actually are and eliminates rests, resulting to a 
more attractive, less cluttered score. 

However, if you wish to make notes display exactly as entered, in the Display
Score, Display Track or Display Bar dialogs set Extend Isolated Notes to No. 

You must also make sure your display quantization is set to a value equal 
to or smaller than the smallest note duration you are trying to display. 
Otherwise, note durations smaller than the display quantization will not 
be displayed properly.
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