It was in the Middle Ages that people first began to think of using lines to represent
musical notes. The very first systems used 11 lines. Why eleven ? Simple - it was the number needed
to fit all the notes the human voice could sing - from the lowest notes of the male bass
up to the highest notes of the soprano.
It was soon realised, however, that such a system was impractical - it was too difficult to
distinguish one note from another on the huge staff.
Solution to the Staff Crisis
To solve the problem, the 11-line staff made way for a variety 5-line staffs.
Each 5-line staff in itself was capable of holding the entire range of any voice.
A system of symbols known as Clefs was used to distinguish which set of five lines
was in operation and that is the system we use to this day.
A letter G over the second line from the bottom indicated the G clef. This was the
clef used by the highest 'treble' voice - its name today is the treble clef.
Similarly, a letter F over the second line from the top indicated the F clef. This staff
was used by the lowest 'bass' voices - it is of course, the bass clef.
There are many other clefs, but the two other most commonly-used clefs today are the
alto clef, used by viola players in particular:
and the tenor clef, used by trombonists and various other instruments.