Speech and singing are processed in different parts of the brain, so people with severe aphasia that can't speak--or can only speak a few words--are able to sing fluently. The guy in the video reminds me of a former patient of mine that had severe aphasia and apraxia (difficulty with motor planning-so he know what to say, but can't physically say it) of speech. He couldn't say any words volitionally, but could swear just fine. lol He could also sing "happy birthday" perfectly fluently. Thank you for sharing this. It brought tears to my eyes. I am going to share with my speech therapist colleagues.