Classical guitar for repertoire of all periods is sometimes critically viewed: Torres and post-Torres style modern guitars (with their fan-bracing and design) have a thick and strong tone, very suitable for modern-era repertoire. However, they are considered to emphasize the fundamental too heavily (at the expense of overtone partials) for earlier repertoire (Classical/Romantic: Carulli, Sor, Giuliani, Mertz, ...; Baroque: de Visee, ...; etc.). "Andrés Segovia presented the Spanish guitar as a versatile model for all playing styles" to the extent, that still today, "many guitarists have tunnel-vision of the world of the guitar, coming from the modern Segovia tradition". While fan-braced modern
History of the classical guitar early 19th century, the guitar evolved into a six-string instrument, phasing out courses by preference to single strings. These six-string guitars were still smaller than the modern classical guitar. The design of the modern classical guitar can be attributed to Antonio de Torres. The construction of these guitars has been considered the standard in "traditional" instruments since the mid 19th century. Contemporary classical guitars follow the Smallman design which replaces the fan braces with a much lighter balsa brace attached to the back of the sound board with carbon fiber. The balsa brace has a honeycomb pattern and allows the