Who established the basic organization of string quaeret and was music teacher?

Guido D'Arezzo established the basic organization of string quartet and was a music teacher. He was an Italian Benedictine monk who lived from approximately 991 to 1050 AD. He is best known for his work in music theory, particularly for his invention of the solfège system, which uses the syllables _do, re, mi, fa, sol, la, and ti to represent the seven notes of the musical scale._

Guido's work in music theory was revolutionary for his time. He was the first to propose a system of notation that accurately represented the pitch of notes, and he also developed a method of teaching music that was more accessible to laypeople. These innovations helped to spread the knowledge of music throughout Europe and eventually led to the development of the modern musical notation system.