To force the display of the key signature
in a measure
Click the Measure tool , and then double-click
barline handle of the measure in which you want the key signature to appear.
The Measure Attributes dialog box appears.
From the Key Signaturedrop-down menu, choose Always Show.
Click OK (or press
ENTER).
You can also hide a key signature in a measure where it would normally
appear by choosing Always Hide.