He's collaborating on a series of special-edition guitars with musicians like Roger McGuinn of the Byrds, whose tricked-out 12-string comes, signed, in a black denim case.

FORBES: Stringing them along

And I started playing the 12-string guitar after really hearing Pete Seeger play and recording things like "Tambourine Man" with Jim McGuinn(ph), Roger McGuinn(ph), and so this guitar - I'm so glad you asked about this guitar because this is patterned after a D-40, a Martin D-35 that I played for years, and it's my signature Judy Collins Martin guitar.

NPR: Judy Collins, From Both Sides Now