Mandolin are used. Usually, courses of 2 adjacent strings are tuned in unison. By far the most common tuning is the same as violin tuning, in scientific pitch notation G–D–A–E, or in Helmholtz pitch notation: g–d′–a′–e″. Note that the numbers of Hz shown above assume a 440 Hz A, standard in most parts of the western world. Some players use an A up to 10 Hz above or below a 440, mainly outside the United States. Other tunings exist, including "cross-tunings", in which the usually doubled string runs are tuned to different pitches. Additionally, guitarists may sometimes tune a mandolin to
Electric violin and carbon fibres, are used in the build process. They are often seen as "experimental" instruments, being less established than electric guitar or bass. Hence, there are many variations on the standard design, such as frets, extra strings, machine heads, "baritone" strings that sound an octave lower than normal, and sympathetic strings. Luthier Yuri Landman built a 12 string electric violin for the Belgian band DAAU. The strings on this instrument are clustered in four groups of three strings tuned unison creating a chorus. Also the instrument features an extra pickup in the tail piece for extra amplification of string