Musical Notation is the system of symbols used to describe a music.
History of Musical Notation
The ancestors of modern symbolic music notation originated in the Catholic church, as monks developed methods to put plainchant (sacred songs) to paper. The earliest of these ancestral systems, from the 8th century, did not originally utilise a staff, and used neums (or neuma or pneuma), a system of dots and strokes that were placed above the text. Although capable of expressing considerable musical complexity, they could not exactly express pitch or time and served mainly as a reminder to one who already knew the tune, rather than a means by which one who had never heard the tune could sing it exactly at sight.
Various modifications were made to address this issue, but the breakthrough came with the staff notation system of Guido of Arezzo. In Guido's system, each staff consisted of 4 horizontal lines. The vertical positions of each mark on the staff indicated which pitch or pitches it represented (pitches were derived from a musical mode, or key). Although the 4-line staff has remained in use until the present day for plainchant, for other types of music, staffs with differing numbers of lines have been used at various times and places for various instruments. The modern system of a universal standard 5-line staff was first adopted in France, and became widely used by the 16th century (although the use of staffs with other numbers of lines was still widespread well into the 17th century).
Because the neum system arose from the need to notate songs, exact timing was initially not a particular issue as the music would generally follow the natural rhythms of the Latin language. However, by the 10th century a system of representing up to four note lengths had been developed. These lengths were relative rather than absolute, and dependeded on the duration of the neighboring notes. It was not until the 14th century that something like the present system of fixed note lengths arose. Starting in the 15th century, vertical bar lines were used to divide the staff into sections. These did not initially divide the music into measures of equal length (as most music then was far less rhythmic than in later periods), but appear to have been introduced as an aid to the eye for "lining up" notes on different staffs that were to be played or sung at the same time. The use of regular measures became commonplace by the end of the 17th century.