![Steve Vai Knappsack video](https://cdn.mos.cms.futurecdn.net/3C94rHEh7ZcuERDkXASx3Y-320-80.jpg)
Steve Vai unveils new song Knappsack, which he shreds entirely with one hand
As he recovers from trigger finger and shoulder surgery, the virtuoso offers up a scorching playthrough that would be near-impossible for most players with two fully functioning hands