John Warden’s guitar workshop, Warden Custom Guitars, is located next to the barn, on his property in Woodstock. Warden, began building and repairing guitars when he was 16 ‚ about the same time as the original 1969 Woodstock festival, in Bethel, N.Y. Over the years he’s been entrusted with repairing the acoustic instruments of some of the world’s best guitarists, ranging from classical virtuoso Andres Segovia to Nils Lofgren, the Bethesda-raised guitarist, best-known for his work in Bruce Springsteen’s E Street Band.