A clef (French for key) is a symbol used in musical notation that assigns notes to lines and spaces on the musical staff. A clef can be thought of as assigning a certain note to a specific line on the staff; adjacent spaces are assigned the notes that follow logically.

There are three commonly used types of clef symbols: the G clef, the F clef, and the C clef, All of these clef symbols intentionally resemble the cursive forms of their respective letters. They have letter names because they assign the note with that name to a particular line on the staff.

Writing an "8" immediately above a clef symbol shifts the notes of the staff up an octave; likewise, writing the 8 beneath the clef symbol shifts the notes down an octave. This notation is used mostly for the G and F clefs.

		

Table of contents
1 The G Clef
2 The F Clef
3 The C Clef

The G Clef

The G clef assigns the note G to a line on the staff, determined by the curl of the "G" symbol. It is normally placed on the staff with the spiral originating from the second line; this usage of the G clef is so common that the name treble clef is often used as a synonym (see below), but the G clef can be placed on other lines: in the baroque period, for example, the G clef was sometimes placed on the first line of the staff for music with a high range. The G clef on the bottom line is called "French Violin clef" which works for Eb clarinet or Eb trumpet music.

The Treble Clef

The treble clef is probably the most widely-used clef, followed by the bass clef. It uses the G clef symbol to assign the note G above middle C to the second line from the bottom of the staff. Most woodwind instruments read treble clef, as well as high brass, violins, and tuned percussion. On the piano, the right hand usually is written in treble clef, while the left hand is written in bass clef.


The treble clef

The F Clef

Two symbols, both a stylized letter F, are used to represent the F clef, although the one below is more commonly used. The two dots of the F clef surround the line that represents the note F. The most common use of the F clef is the bass clef, which places F on the 2nd line from the top of the staff; the name "F clef" is frequently used to mean the bass clef. However, the F clef has historically been used on other lines of the musical staff, most notably on the middle line, when it is known as the baritone clef. This usage is nowadays very rare, however.

The Bass Clef

The bass clef uses the F clef to assign the note F immediately below middle C to the second line from the top of the staff. Most lower-pitched instruments, such as the lower brass, strings and woodwinds read bass clef. On the piano, the left hand is usually written in bass clef, while the right hand is written in treble clef.


The bass clef

The C Clef

The C clef resembles two backwards letter 'C's, one above the other. The line that falls between the 'C's is assigned the note middle C. There are two common clefs that use the C clef symbol: The alto clef, which assigns C to the middle line of the staff, and the tenor clef, which assigns C to the second line from the top of the staff. The C clef is sometimes also used to indicate the mezzosoprano or flautalto clef, which assigns C to the second line from the bottom of the staff. The C clef on the first line means soprano clef which works for violin and the clarinet in A.

The Alto Clef

The alto clef uses the C clef to assign the note middle C to the middle line of the staff. The alto clef is used by violas and occasionally by trombones. It is also used in vocal music.


The alto clef

The Tenor Clef

The tenor clef uses the C clef to assign the note middle C to the second line from the top of the staff. Cellos read the tenor clef; it is also used in vocal music. Bassoons and trombones, which normally read the bass clef, use the tenor clef to avoid excessive ledger lines in extended high passages.


The tenor clef

But why all these different clefs? Although only four are common today, as many as eight have been used previously. The reason is, oddly not a musical but a mechanical one. In the days of early printing presses (i.e, the renaissance) leger lines were difficult to print, so a wide variety of clefs were subsequently used.