Solution
You can change the spacing either programmatically or with the user interface.
User interface
The spacing can be changed by hovering over one of the side bands until the double headed arrow appears. You then drag the side band away from the central band, as seen below:
If this is unsuccessful, try resetting the cursor by right clicking >> Cursor >> Reset as seen below:
NOTE: If this doesn't work check you aren't over the central band, as dragging this will move all the lines relative to the X axis.
Programmatically
In order to change the line spacing programmatically please look at the example code on the following page:
Property: Sidebands for SidebandCursor.