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
Classical guitar 3rd and 4th strings). To achieve tremolo effects and rapid, fluent scale passages, the player must practice alternation, that is, never plucking a string with the same finger twice in a row. Using p to indicate the thumb, i the index finger, m the middle finger and a the ring finger, common alternation patterns include: Music written specifically for the classical guitar dates from the addition of the sixth string (the baroque guitar normally had five pairs of strings) in the late 18th century. A guitar recital may include a variety of works, e.g. works written originally for the lute