up veterans with some of the world's biggest stars. roger waters, front man of pink floyd. and after seeing the crowd at last year's stand up for heroes event, roger had an idea. >> i thought what if they would let me try and put a band together that had a bunch of the guys in it? these guys. >> reporter: they became the wounded warriors band. this is a dream i can't imagine you ever thought of. >> no. never, ever imagined it. ♪ knock, knock, knocking on heaven's door ♪ >> reporter: together on the stage might not always see their scars, but you will see their souls. bob woodruff, abc news, new york. >> and here's some of the stats here. one in every 50 servicemembers who sung who served in either of the wars sustained an injury. one in 25, 20%, post-traumatic stress, traumatic brain injury and depression. >> if you didn't serve, serve those who did with a quote that came out of last night. f last night. a quote that came out of last night. you disgust me.