STEP SEQUENCER
The Keyboard Editor view lets you set the pitch of notes in the Step Sequencer. It is a set of piano keyboards (rotated 90 degrees counter clockwise) - one for each dot in the Step Sequencer. Note that actions you do in the Keyboard Editor have effect on ALL selected channels.

You can also drag all notes at once - hold Ctrl and then drag a note, the rest will follow.
Note: There is a maximum of 64 steps in the Step Sequencer. This is controlled by the Pattern Length control.