The history of folk music is intertwined with Martin Guitars and one of the seminal groups from the folk heyday was Peter, Paul, and Mary. This HD-28 Centennial Commemorative Model, of which only 2 were made, was designed to celebrate the group's 50 years of playing together. Peter Yarrow designed the artwork and it was photographed, along with the group's signatures, and expertly applied by Martin. The guitar's brother is now housed in the Folk and Americana Roots Hall of Fame at the Wang Center in Boston.