Classical guitar may vary, but the typical shape is either "modern classical guitar" or that "historic classical guitar" similar to the early romantic guitars of France and Italy. Classical guitar strings once made of gut are now made of such polymers as nylon, with fine wire wound about the acoustically lower (bass side) strings. A guitar family tree may be identified. The flamenco guitar derives from the modern classical, but has differences in material, construction and sound. Today's "modern classical guitar" was established by the late designs of the 19th-century Spanish luthier, Antonio Torres Jurado. The classical guitar has a long history
Ten-string classical guitar of Yepes Ramírez III considered adding sympathetic strings to the classical guitar. He sought advice from the leading classical guitarists of the time, notably Andrés Segovia and Narciso Yepes, both of them players of Ramírez six-string guitars. Eventually they came up with a ten-string guitar. In "Ser Instrumento", Yepes mentions that the reasons that led him to carry out the "design" ("diseño"), of his instrument were acoustical/physical (""físicas"") and musical (""musicales""). After some "initial protest" that the 10-string guitar envisioned by Yepes was "impossible" to construct, Ramírez agreed to the commission and completed the first of these instruments in March 1964. Yepes