Scordatura

Scordatura is the re-tuning of one or more strings to a non standard pitch. On a regular instrument, it is advisable to not re-tune any string a semitone higher than normal and lower than a fifth.
When strings are detuned, excess bow pressure will result in a distortion of pitch.
The use of scordatura will also alter the timbre of the instrument. It can also be used to enhance sympathetic resonance.

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