EVENT: New York Guitar Festival at The Greene Space The South African guitarist Derek Gripper takes traditional West African music for the kora, a 21-string harp, and somehow manages to play it live on a 6-string guitar. We’ve spoken to some pretty impressive guitarists here in NY about Gripper, and none of them can figure out how he does it. Tonight, we’ll find out, because he’s performing in WNYC’s Greene Space as part of the NY Guitar Festival. Check the full lineup above.