Those are the Expresskeys. They are personalizable buttons for easy acces to your selected commands. For example, mine has alt, shift, ctrl, and the Windows key.
Go to the Gradient Picker at the top of the screen and click on black and white. Then, hold Shift, drag the corners to your whole image that you want...
Most string instruments are designed to have the bowing or strumming in the right hand and the fingering or fretting in the left. Although some are made so you can...