This project is to build an editable grid. This is for a musical project. Rows are pitch indexes for notes. Columns are times for notes. It should use a HTML5 Canvas. There are two modes: create and delete. When the user clicks at a point in create mode, an entry should be created. When user clicks a point in delete mode, an entry should be deleted. Each entry is a rectangle and it represents a note at a particular time with a particular pitch.
time 0 time 1 time 2
pitch 0 xxxxxx
ptich 1 xxxxxx
ptich 2 xxxxxx
Take a look at the screenshot for an example.