Guidod'Arezzo

Gui·do d'A·rez·zo (gwēʹdō dä-rĕtʹsō) or Guido A·re·ti·no (är'ĕ-tēʹnō), 990?-1050.

Benedictine monk and music theorist who devised the four-line staff, thereby allowing precise musical notation.

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