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
Mute violin part of the first violin in his first string quartet of 1914 to be played by a mute violin. In a recording of his five string quartets by the Schönberg Quartet (Olympia OCD 457, 1994) the effect of the mute violin was imitated by an extra heavy sordino on an 'ordinary' violin. Mute violin The mute violin is a violin without or with a very shallow sound box. The instrument has a quiet, lean sound. The mute violin can be used as an exercise instrument in situations where the sound of a violin is experienced as annoying by neighbouring people.