Cross tuning if played in regular tuning, while the sounded pitch is altered. Cross tuning is commonly used on the fiddle in folk music of Appalachia, the southern United States and Scandinavia. The fiddle may be re-tuned in any number of ways in these musical idioms, but there are two common re-tunings. While the standard tuning for open strings of the violin is GDAE—with the G being the tuning of the lowest-pitched string and the E being the tuning for the highest-pitched string—fiddlers playing tunes in the key of D major sometimes employ a tuning of ADAE. In this tuning the open
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,