walmark play the piano and you can see he's no ordinary kindergartner. he has an extraordinary talent and an even more extraordinary story. ethan is autistic. >> when he plays, every disability disappears, and he's just a regular kid, and it just makes him so happy. he really feels it. >> reporter: his first piano performance was when he was just 1 year old. >> he actually started playing on a kid's piano. and he, all of a sudden -- we were in the kitchen and heard "mary had a little lamb" and "twinkle, twinkle." we thought, well, gee, that's odd. is that on "sesame street"? there's ethan banging out the notes. it was pitch perfect. >> reporter: he's moved on to elton john, the beatles, coldplay, adele, beethoven and mozart, all played by memory. it wasn't until his mom uploaded a video of him to youtube playing billy joel's "the piano man" that ethan went viral. as of today, more than 1 million people throughout the world have