 Cumpiano's career spans almost forty years of hand-crafting all sorts of fretted stringed instruments from the North American, European and Latin American traditions.In 1985, his interests turned to the stringed instrument traditions of his native Puerto Rico and over the years Cumpiano became an authority on the craft and traditions that surround the "national instrument" of Puerto Rico, the ten string "cuatro".He has built numerous cuatros for musicians in the United States and also has crafted cuatro variants of his own design