Walter writes a song celebrating President Obama. Walter then applies for and receives a copyright to the song. If Stephen uses the song at concerts, on his TV show, and puts Walter's song on a CD, has Stephen violated Walter's copyright?
a. Yes, unless Stephen changed the words enough that it has become a parody.
b. Yes, if Stephen makes any money while using Walter's song.
c. No, if Stephen used Walter's exact song without modification.
d. No, because the song is about the President.