Nice sounding performance. The guy simply played the keyboard and sang along to a (commercial?) midi file utilizing the PA3X's vocal harmonizer.
It's obvious because when he's playing the guitar solo and concurrently operating the PB stick with his LH (beginning @ 2:47),
the song's chords continue to change without him having to trigger the changes himself.
I would love to hear this same song performed on the PA3X, but instead, performed in 'auto accompaniment' arranger mode.