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
Violin technique and is best executed with a sinuous movement of the bow arm. Sometimes the same pitch as an open string will be fingered on an adjacent string, so that the alternation is between the same note on two strings, one stopped, one open, giving a rhythmic pulsating effect. Bariolage was a favorite device of Joseph Haydn, who used it for example in his string quartet Opus 50 no. 6, and in the "Farewell" Symphony. It is also prominently featured in the Preludium of Bach's Partita No.3 in E major for solo violin. Playing an open string simultaneously with a stopped