All you need to make a beat is bang two sticks together. A child could do it (confidential to percussionists: we're not really serious. Please don't sue for libel). YouTube performers Wax and Herbal T took this idea to its logical conclusion and made a rap song using sounds from Herbal T's toddler son's playground session.
A six-year-old named Ethan has been making the rounds on the internet for his lively, expressive performance of Billy Joel's "Piano Man." The original video also mentions that he's "on the autism spectrum," which has probably fueled people's interest it.