Keyboard only editor for piano roll area

I want adding, editing, and removing notes to be doable on the piano roll as a purely keyboard activity.

Proposal: a vim-style interface where there is a cursor that travels around the piano roll area box by box.

space bar puts in a note, goes into note insert mode (hitting l / h lengthens / shortens it). Hitting escape goes back to cursor.
hitting i on an existing note triggers the same behavior that editing an existing note does.

If this sounds good, i can start trying to figure out how to add it.

Start by locating the piano roll area and its existing note insertion and editing behavior. Review how cursor movement, note selection, and keyboard input currently work, then define the vim-style modes and navigation rules before implementing them. Done means adding, editing, and removing notes is possible without using a mouse.

Written by the indexing model from the issue text.