Guido of Arezzo

Early French-Italian Medieval composer and theorist Guido of Arezzo (c. 995-c. 1050) invented such conventions as the lined musical staff and began a system which became the current clefs. A Benedictine monk, he also developed the use of the system of solmisation using the syllables ut, re, mi, fa, sol, and la. His work drew such attention that he received a papal audience in 1028 before John XIX. His major theoretical work was Micrologus de disciplina artis musicae. His contributions led to modern Western music and helped begin composition instead of improvisation as the major form of creating new music.