Song titles, book titles, movie titles, and etc. are generally unprotected. You are typically free to use and reuse them however you want as long as you don't violate trademark rights. An unpublished essay for school would be hard pressed to violate trademark rights. Snagging a song title for an essay wouldn't be plagiarism in my book and I would be very surprised if your teacher thought it was unless the assignment specifically restricted that sort of thing.
Answered on Dec 20th, 2012 at 12:10 PM