A good warm up activity / set induction for War or Social Issues themed lessons. Words omitted from the lyric are vocabulary that can be related to the theme. Link to the video is below. Can use other versions of the song as well. They are all available on youtube. Just search for it. Or to be more creative can play the guitar while sing to the song OR get students that can play to play the song in class at the end of lesson as reward for them. Enjoy!