A clef (from the French for "key") is a musical symbol used to indicate the pitch of written notes. Placed on one of the lines at the beginning of the staff, it indicates the name and pitch of the notes on that line. This line serves as a reference point by which the names of the notes on any other line or space of the staff may be determined.
|This clef...||is called...||and assigns the note...||to the line...|
|the G-clef||G above Middle C||encircled by the curl of the clef.|
|the C-clef||Middle C||that passes through the center of the clef.|
|the F-clef||F below Middle C||between the two dots of the clef.|
Once one of these clefs has been placed on one of the lines of the staff, the other lines and spaces can be read in relation to it.
The use of three different clefs makes it possible to write music for all instruments and voices, even though they may have very different tessituras (that is, even though some sound much higher or lower than others). This would be difficult to do with only one clef, since the modern staff has only five lines, and the number of pitches that can be represented on the staff, even with ledger lines, is not nearly equal to the number of notes the orchestra can produce. The use of different clefs for different instruments and voices allows each part to be written comfortably on the staff with a minimum of ledger lines. To this end, the G-clef is used for high parts, the C-clef for middle parts, and the F-clef for low parts - with the important exception of transposing parts, which are written at a different pitch than they sound, often even in a different octave.
In order to facilitate writing for different tessituras, any of the clefs may theoretically be placed on any of the lines of the staff. The further down on the staff a clef is placed, the higher the tessitura it is for; conversely, the higher up the clef, the lower the tessitura.
Since there are five lines of the staff, and three clefs, it might seem that there would be fifteen possible clefs. Six of these, however, are redundant clefs (for example, a G-clef on the third line would be exactly the same as a C-clef on the first line). That leaves nine possible distinct clefs, all of which have been used historically: the G-clef on the two bottom lines, the F-clef on the three top lines, and the C-clef on any line of the staff except the topmost, earning the name of "movable C-clef". (The C-clef on the topmost line is redundant because it is exactly equivalent to the F-clef on the third line; both ways of writing this clef have been used).
Each of these clefs has a different name based on the tessitura for which it is best suited.
In contemporary music literature, only four clefs are used regularly: the treble clef, the bass clef, the alto clef, and the tenor clef. Of these, the treble and bass clefs are by far the most common.
An obelisk (†) after the name of a clef indicates that that clef is now obsolete.
When the G-clef is placed on the second line of the staff, it is called the "treble clef". This is by far the most common clef used today, and the only G-clef still in use. For this reason, the terms G-clef and treble clef are often seen as synonymous. It was formerly also known as the "violin clef". The treble clef was historically used to mark a treble, or pre-pubescent, voice part.
The lines on the treble clef staff correspond to the letters E G B D F, and can be remembered with the sayings Every Good Boy Does Fine, Every Good Boy Deserves Favour, Every Good Bird Does Fly or Every Good Boy Deserves Football [the last is most commonly used in England]. The spaces on the treble clef staff correspond to the letters F A C E.
This clef is used for the bagpipes, violin, flutes, oboe, English horn, all clarinets, all saxophones, horn, euphonium (occasionally), trumpet, guitar, vibraphone, xylophone and handbells; for the upper part of keyboard instruments like the piano, organ, harp, and harpsichord (of which the lower part is usually written in the bass clef); for the highest notes played by the cello (the old convention was to write an octave higher, unless preceded by a tenor clef), double bass, bassoon, trombone (which otherwise use the bass and tenor clefs), and viola (which otherwise uses the alto clef); and for the soprano, mezzo-soprano, alto, contralto and tenor voices. The tenor voice is often written using an octave clef (see below) or double-treble clef.
The notes from the bottom line to the top line are:
E4, F4, G4, A4, B4, C5, D5, E5, F5
When the G-clef is placed on the first line of the staff, it is called the "French clef" or "French violin clef".
This clef is no longer used. Formerly, it was used by the flute and violin, especially in parts published in France in the seventeenth and eighteenth centuries.
Its placement causes the note names on the staff to be identical to those of the bass clef.
When the F-clef is placed on the fourth line, it is called the "bass clef". This is the only F-clef used today, so that the terms "F-clef" and "bass clef" are often regarded as synonymous.
The lines on the bass clef staff correspond to the letters G B D F A, and can be remembered with either the saying Good Boys Deserve Fruit Always, Good Boys Deserve Fudge Always, Great Big Dogs Fight Animals. The spaces on the bass clef staff correspond to the letters A C E G, and can be easily remembered by saying the phrase All Cows Eat Grass or All Cars Eat Gas.
This clef is used for the cello, euphonium, double bass, bass guitar, bassoon, contrabassoon, trombone, tuba, and timpani; for the lower part of keyboard instruments like the piano, organ, marimba and harpsichord (of which the upper part is usually written in treble clef); and for the lowest notes of the horn; and the baritone and bass voices. Double Bass and Bass guitar is notated in bass clef an octave higher than the sound it makes.
The notes starting on the bottom line bottom to top line are:
G2, A2, B2, C3, D3, E3, F3, G3, A3 (or when used for Double Bass/Bass Guitar: G1, A1, B1, C2, D2, E2, F2, G2, A2)
When the F-clef is placed on the third line, it is called the baritone clef.
This clef is no longer used. Formerly, it was used to write the baritone part in vocal music.
When the F-clef is placed on the fifth line, it is called the subbass clef. This is unique among the other F-clefs in that it is the same note arrangement as the treble clef.
This clef is no longer used. Formerly, it was used to write low bass parts, e.g. in the works of Heinrich Schütz.
When the C-clef is placed on the third line of the staff, it is called the alto clef. As with all C-clefs, this line indicates the position of middle C.
This clef (sometimes called the viola clef) is currently used for the viola, the viola da gamba, and the alto trombone. Formerly, it was used for the alto voice and by instruments playing a middle part (oboes, recorders, etc.) It occasionally turns up in keyboard music to the present day (Brahms' Organ chorales, John Cage's Dream for piano).
The notes from the bottom line to the top line are:
F3, G3, A3, B3, C4, D4, E4, F4, G4
When the C-clef is placed on the fourth line of the staff, it is called the tenor clef.
This clef is used for the upper ranges of the bassoon, violoncello, euphonium, double bass, and trombone (which all use the bass clef in their lower and middle ranges, and in their extreme high ranges, the treble clef as well). Formerly, it was used by the tenor part in vocal music but its use has been largely supplanted either with an octave version of the treble clef when written alone or the bass clef when combined on one staff with the bass part.
Occasionally in the past, the C-clef was placed on the fifth line, and it is called the baritone-clef, like the baritone F-clef on the third line, to which it is exactly equivalent. Because of this equivalency, it was rarely used in the past; the baritone F-clef was used instead.
When the C-clef is placed on the second line of the staff, it is called the mezzo-soprano clef.
This clef is no longer used. Formerly, it was used in vocal music to write mezzo-soprano parts.
When the C-clef occurs on the first line of the staff, it is called the soprano clef.
This clef is no longer used. Formerly, it was used in vocal music to write soprano parts. The soprano trombone uses this clef too. Although this trombone is seldom used today, some works of J.S. Bach call for it.
This is most often found in tenor parts in SATB settings, in which a treble clef is written with an eight below it, indicating the pitches sound an octave below the written value. As the true tenor clef has generally fallen into disuse in vocal writings, this "octave-dropped" treble clef is often called the tenor clef. The same clef is sometimes used for the baritone horn. In some scores, the same concept is construed by using a double clef -- two G-clefs overlapping one another.
At the other end of the spectrum, treble clefs with an 8 positioned above the clef is often used in piccolo, penny whistle, soprano recorder, and other high woodwind parts and is sometimes known (informally) as the "sopranino clef".
The F clef can also be notated with an octave marker. The F clef notated an octave down is sometimes used for contrabass instruments such as the double bass and contrabassoon and, as the traditional subbass clef has fallen into disuse, that term is sometimes used to describe this clef. The F clef notated an octave up is used for bass recorder and sometimes, though seldom, used for countertenor parts and called the countertenor clef, as it is easy for a bass or baritone to read while singing the part in falsetto. However, both of these are extremely rare (and in fact the countertenor clef is largely intended to be humorous as with the works of P.D.Q. Bach). The unmodified bass clef is so common that performers of instruments and voice parts whose ranges lie below the staff simply learn the number of leger lines for each note through common use, and if a line's true notes lie significantly above the bass clef the composer or publisher will often simply write the part in either the true treble clef or notated an octave down.
Staves with a neutral clef do not always have five lines. Commonly, percussion staves only have one line, although other configurations can be used.
The neutral clef is sometimes used when non-percussion instruments play non-pitched extended techniques, such as hitting the body of a violin, violoncello or acoustic guitar, or when a vocal choir is instructed to clap, stomp, or snap, but more often the rhythms are written with X marks in the instrument's normal staff with a note placed above as to the appropriate rhythmic action.
For guitars and other plucked instruments, it is possible to notate tablature in place of ordinary notes. In this case, a TAB-sign is often written instead of a clef. The number of lines of the staff is not necessarily five: one line is used for each string of the instrument (so, for standard six-stringed guitars, six lines would be used, four lines for the traditional bass guitar). Numbers on the lines show on which fret the string should be played. This Tab-sign, like the Percussion clef, is not a clef in the true sense, but rather a symbol employed instead of a clef.
The clefs developed at the same time as the staff, in the 10th century. Originally, instead of a special clef symbol, the reference line of the staff was simply labeled with the name of the note it was intended to bear: G, F, or C. These were the 'clefs' used for Gregorian chant. Over time, the shapes of these letters became stylized; eventually resulting in the shapes we have today.
Two other clefs have been used as well, the D-clef and the Gamma-clef, indicating the notes now represented by the fourth line of the treble clef and the first line of the bass clef, respectively; but these fell out of use.
Several variant shapes of the different clefs persisted until very recent times. The F-clef was, until very recently, written like this: .
The C-clef was formerly written in a more angular way than now, and many people still use this, or a further simplified K-shape, when writing the clef by hand. The flourish at the top of the G-clef probably derives from a cursive S for "sol", the name for "G" in solfege.
C-clefs were formerly used to notate vocal music, a practice that dwindled away during the late 19th century. The soprano voice was written in 1st line C clef (soprano clef), the alto voice in 3rd line C clef (alto clef), the tenor voice in 4th line C clef (tenor clef) and the bass voice in 4th line F clef (bass clef).
In more modern publications, four part harmony on parallel staves is usually written more simply as:
Alternatively, this is reduced to two staves, the soprano/alto staff with a treble clef, and tenor/bass staff marked with the bass clef.