>> this is 33-year-old anthony dias.e discovered he had a brain tumor two weeks after his son was born. his motor skills and speech were affected. the doctors discovered the tumor that had to be removed. here he is in surgery and they let him bring in his guitar and sing. when people get brain surgery they use anesthesia but you're not put under where you're asleep. the brain has no pain censors so you can talk to your doctors and this is helpful to them so they know if there's been injury to the areas of your brain that control your speech or your movement. >> wouldn't you freak out while you're there? brain surgery happening, you get to the chorus and you get into it and you move. the scalpel goes the wrong way. >> wouldn't this help you relax and take your mind off the fact someone is poking around in your mind. >> no! it's freaky. >> what if the music just stopped and the doctors are like [ laughter ] >> older brothers, either love them or -- >> you love to hate them. >> for reasons like this. ♪ >> this is why mom do