Quick Answer: Drag the left and rights ends of blue bar on the right end of the piano roll to change the zoom level of the piano roll.
Zoom in and out in the piano rollThe piano roll in Liquid Notes is selectable via the tab Piano Roll at the upper middle section of the program window. It is used to display single MIDI events of different instrumental tracks.
Depending on the predefined size of the piano roll, this may cause the chord regions to change in height and MIDI events to become hard to read.
To counteract this, a blue bar to the right of the piano roll acts as zoom tool:
Drag the bar up or down to move the MIDI events in the selected work area. Or, drag the left or right end of the bar with the mouse to zoom in and out of this area.