The Composer view displays an environment with a Piano Roll keyboard on the left side and its timeline on the right side which allows you to create and edit the clip notes with various tools.
All note actions are applied to currently selected notes or to all notes if no notes are selected. Manually created notes will always be snapped to the grid. To create notes simply press where you want the notes to be created. If you press and drag you can create a long note. If you press on an already existing note and drag this will move the note, but if you press and drag the right end of a note it will change its duration. (On iOS you can zoom the view using two fingers). To make a selection of notes you can press on an empty space and drag diagonally to create an area of selection.
Notes created in the composer also create Note, Velocity and Time Offset automations for their respective steps.
SHIFT functions: