I’ll give him, he is very entertaining to watch. And I guess you’ve got to be able to throw a ball exactly where you want it to be a professional juggler, but come on…do you think that is a real (albeit specially modified) keyboard? Is he really producing the sound by the balls hitting the keys (maybe it is like a xylophone) or is he just keeping the correct timing while something/someone else generates the sound?
Nope, it’s real. It’s not the same guy, but Dan Menendez The Piano Juggler does the same act. The first clip on his website, the Ellen Degeneres show, gives you a closeup look at how it works. No tricks. Just phenomenal hand-eye coordination, and a LOT of practice.
In the OP’s clip, it looks like repeated notes are being sounded by different keys. So I’m guessing the setup plays the notes/chords in sequence every time a ball hits anywhere on the keyboard. Or else only the keys intended to be played are activated in sequence, which seems to me to be much harder and so less likely.
Besides, the keys look so narrow that it would be very hard NOT to hit two adjacent keys at once.