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 fingers on the right spots without such indications but from practice and experience. To attain good intonation, violin players train their fingers to land in the right places, learning to hear when a note is in or out of tune, and cultivating the ability to correct the pitch rapidly and automatically as notes are being played. "Singing" the note mentally helps to land in the right spot. (In practice, intonation may be checked by sounding an adjacent open string, and listening for the interval between the two notes.) Although adjusting to the desired pitch after landing the finger is indeed