Very special stuff.
There's about 4 or 5 different techniques involved in this style. Pioneered by many great players before this gentleman, who I must say is as uniquely talented as the preiviously thought of. For example Eric Roche had 7 microphones built into his acoustic for this exact type of style.
An honorable mention from Tommy is in Eric's book.
It does seem in recent years (last 7) that this type of playing has become more wide spread now. That's such a great thing!
I can testify that this type of style does grab people attention in bar's.
Try to take each method & break things down slowly.
Timing on wood knocks, different area's of wood tone knock's (body sound bass to trebile) harmonic slaps', stabb's, accuracie of left had, then right.
Conjunction of all methods bit by bit. Alt tunes are a go to but standard tuning is equally as important & do'able.
Doesn't take long to have a go but it does take years to refine the art.
He's completely there in the moment, he know's his instrument. Rivating stuff.
Maybe the best way to learn is by following/setting a pulse.
Simple stuff, like on the 4th meassure of chord try hitting the 12th harmonics.
Each rhythmic choice you make can give you different results.
knuckles, finger tips, palm, nails, side of the hand will all give different tonal variations around the wood's surface area.
Experiment & have fun.
I've found you a special video of my old teacher to help you. I miss him.