scordatura

noun, plural scor·da·tu·re [skawr-duh–too r-ey; Italian skawr-dah-too–re] /ˌskɔr dəˈtʊər eɪ; Italian ˌskɔr dɑˈtu rɛ/, scor·da·tu·ras. Music.

1. the tuning of a stringed instrument in other than the usual way to facilitate the playing of certain compositions.