A song that never made 'Joshua Tree'

Growing up, The Joshua Tree album by U2 was one of my favorites. I listened to it over & over, and could sing along with most every song. So it was interesting to learn this week that u2 is releasing a few bonus tracks that didn't make the original record, but were written around the same time. Here's a video clip of Bono explaining the background on 'Wave of Sorrows' and then playing it.