These operations are common to most editors, and behave similarly to what you should be used to from other applications.
Most actions in Zrythm are undoable, which means that you can go back to the state before that action was made, or you can come back to a state that you undo’ed from.
For example, if you create a MIDI note and press undo, the MIDI note will be deleted (Zrythm goes back into the state where the MIDI note did not exist). Pressing the Redo button will create the note again, and you can go back between Undo and Redo as many times as you want.
It is also possible to go back/forth more than one action, by clicking the arrow next to the Undo and Redo buttons.
The shortcuts for undo and redo are Control-z and Control-Shift-z.
If you Undo and then perform a new action, the Redo history will be deleted.
Delete and copy the selected objects and save them in the clipboard so that they can be pasted elsewhere. The shortcut for cutting is Control-x.
Copy the selected objects to the clipboard so that they can be pasted elsewhere. The shortcut for copying is Control-c.
Paste the objects currently in the clipboard to the current playhead position. The shortcut for pasting is Control-v.
Create a copy of the selected objects adjacent to them. The shortcut for duplicating is Control-d.
Delete the selected objects. You can also press Delete.