Octave mandolin in unison. Alternate tunings exist in which the strings in some courses are tuned to octaves, rather than unisons, but this is more typical of the Irish Bouzouki. Usually, courses of 2 adjacent strings are doubled (tuned to the same pitch). The standard octave mandolin tuning is G2 G2 • D3 D3 • A3 A3 • E4 E4, so the lowest open strings are tuned to the lowest 'G' on the guitar, and the highest strings are tuned to the same 'E' as the highest string of the guitar. This tuning is one octave below the mandolin (or a fourth
Viola of a viola is wrapped around a peg near the scroll and is tuned by turning the peg. Tightening the string raises the pitch; loosening the string lowers the pitch. The A string is normally tuned first, typically to a pitch of 440 Hz or 442 Hz. The other strings are then tuned to it in intervals of perfect fifths, sometimes by bowing two strings simultaneously. Most violas also have "adjusters"—"fine tuners", that make finer changes. These adjust the tension of the string via rotating a small knob at the opposite or tailpiece end of the string. Such tuning is