Measures adding and deleting

You can add a single measure at the current selection point by pressing Insert. Shift+Insert appends the new measure to the selected measure.

To add many measures, you can do this from the 'Add Measures' dialog. This can be brought up through the 'Measure' button on the left, or by pressing

/ a 0 (zero)

Deleting the selected measures can be done from the 'Measures' menu on the left, or by pressing

/ a 1.

Note the insert and delete key behavior is asymmetric. The Delete key is used to toggle notes to rests, and also I thought this made it too easy to accidentally delete a lot of music.