2 The basics
2.1 The staff
The idea of placing notes on a set of horizontal lines – the staff –to show the relationship of various pitches with each other – staff notation – emerged in western music towards the end of the ninth century. Originally, each pitch was allocated its own line, but the Italian music theorist, Guido of Arezzo, who lived during the early eleventh century, suggested that lines should be drawn for every other pitch, so that alternate pitches sat on the lines and the remaining pitches were placed in the intervening spaces between the lines.
This principle was soon adopted and has remained in force in traditional western music notation to the present day. The number of lines included in the staff has varied depending on the range of the music being notated. However, the norm has evolved as the five-line staff, shown in Example 1.
As shown in Example 2, if we place pitches in the form of note heads on the staff, information about the relationship of the pitches with each other is produced.