In Add Notes mode notes can be drawn by moving the mouse horizontally while keeping the left mouse button down. Clicking the mouse without dragging it will add a note having the same duration as the last one. Notes can be dragged or resized using the mouse in both Select Notes and Add Notes mode.
The name of the chord constituted by the selected notes will be displayed in the editor while selecting.
Right clicking a note pops up a menu to (among other things) split the note or to join it with the previous note.
The Pianoroll editor can be used for step recording. If the vertically oriented piano on the left is clicked while the Ctrl key (Windows) / Command key (Mac) is held down, the corresponding note will be recorded at the current transport position. Also, the transport position will move to the end of the new note. The duration of the new note equals one step of the current grid. You can add the Shift key to go one step to the left before the note is added, so you can easily add a couple of notes at the same position.
Clicking while keeping the Alt key (Windows) / Options key (Mac) down adds a rest (ie. the transport position moves to the right). You can add the Shift key to go one step to the left instead.