Why did titian paint mostly portraits?

Not quite sure

Musical notation is a system which is used to  visually represent music  pertaining to the ear  contend  with instruments or sung by the human voice through  the employment  of written, printed, or different symbols.in the western music tradition, the sound is represented in written form through musical notation.in musical notation, the pitch is indicated exclusively by the position of notes on the lines and spaces of the staff.

Yes because in graphic design you add elements of art into one piece and/or program. although, you place together graphic designs on a computer,  you still have to know about the principles of design which is included in art.

Ball is the direct object, because is the receiver of the action