What is "scordatura"

n. cross-tuning; a system of tuning a musical instrument to pitches other than the accepted standard, for example, tuning one or more strings of a violin to pitches other than the commonly accepted GDAE.

Scordatura (literally Italian for "mistuning"), is a tuning of a stringed instrument different from the normal, standard tuning. It typically attempts to allow special effects or unusual chords or timbre, or to make certain passages easier to play. It is common to notate the finger position as if played in regular tuning, while the actual pitch resulting is altered (scordatura notation). When all the strings are tuned by the same interval up or down, as in the case of the viola in Mozart's Sinfonia Concertante for Violin, Viola and Orchestra, the part is transposed as a whole.