 He also developed the "thinline" cuatro with a body depth of only two inches instead of the traditional three.Among his customers are Arlo Guthrie, Michael Lorimer, John Abercrombie, Country Joe MacDonald, the Todd Rundgren band, June Millington, and Joel Zoss.Cumpiano has taught his craft for over twenty years out of his studio, in schools, during workshops and lectures and through numerous publications.