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
Violin technique intervals of perfect fifths by bowing them in pairs. This puts the open strings in just intonation, which means the lower strings may sound flat compared to their nominal equal-tempered equivalents. In practice, this means some compromises must be made, and the strings not always tuned in perfect fifths, particularly on the viola and cello, where the lowest string is the C, three fifths away from the reference A, making the difference more apparent. Small, temporary tuning adjustments can also be made by stretching a string with the hand. A string may be flattened by pulling it above the fingerboard,