A capo, short for capo d'astro, capo tasto or capotasto [kapo'tasto], Italian for "head of fretboard"; Spanish, capodastro [ka.po'ðas.t?o]; French, capodastre; German, Kapodaster; Portuguese, capodastro, Serbo-Croatian "kapodaster" or just "kap") is a device used on the neck of a stringed (typically fretted) instrument to shorten the playable length of the strings, hence raising the pitch. It is frequently used on guitars, mandolins, banjos, and ukuleles. The word derives from the Italian "capotasto" which means the nut of a stringed instrument. The earliest known use of the term "capotasto" is by Giovanni Battista Doni who, in his Annotazioni of 1640, uses it to describe the nut of a viola da gamba. The first patented capo was designed by James Ashborn of Wolcottville, Connecticut.
Musicians commonly use a capo to raise the pitch of a fretted instrument so they can play in a different key using the same fingerings as playing open (i.e., without a capo). In effect, a capo uses a fret of an instrument to create a new nut at a higher note than the instrument's actual nut.
There are several different capo designs, but most commercial capos consist of a rubber-covered bar that clamps to the instrument's neck in some way to hold down the strings. Capos come in different sizes and shapes for different instruments and fretboard curvatures. The most relevant mechanical factors that vary by type of capo are ease of use, size, degree of interference with the player's hands, and ability to hold down strings uniformly without affecting tuning. All types of capo should be applied after a fresh tuning by laying the barre, descending from above, and directly behind the fret, so that all of the strings have uniform position and pressure. If the strings are bent or mispositioned, the instrument will sound out of tune in the new key. Some types of capo can mar the neck of the guitar if applied incorrectly.
Musicians use capos on many stringed instruments: guitars, mandolins, mandolas, banjos, ukuleles, bouzoukis--virtually any instrument that has strings suspended over a fretted fingerboard. Capos exist for square-necked resonator guitars, some of which do not contact the neck, but clamp above and below the strings.
Song arrangements often cite capo position, just as they cite alternate tunings. When referencing fingerings for a song that uses a capo, the player must determine whether the chart references absolute finger positions, or positions relative to the capo. For example, in tablature, a note played on the fifth fret of an instrument capoed at the second fret can be listed as "5" (absolute) or "3" (relative to capo). Similarly, a D-shaped chord can be referred to as "D" (based on the shape relative to the capo), or E (based on the absolute audible chord produced). Neither method strongly prevails over the other. For this reason, the phrase "chord-shape" is commonly used to clarify that the fingering shape and not the audible pitch is being referred to.
With this concept in mind, if two players wish to play a chord progression with a more harmonious effect, one can play first position chord-shapes while the second player, placing the capo further up the fretboard, plays first or second inversions of the same chord progression using familiar chord-shapes. In this manner, the two guitars create a fuller sound than they would playing in unison. For example, if they play a simple I IV V chord progression together in E the first guitarist plays E A B7 while the second plays the same progression capoed at the 4th fret using C F G7 chord-shapes.
Playing with a capo creates the same musical effect as retuning all strings up the same number of steps. However, using a capo only affects the open note of each string. Every other fret remains unaffected (e.g., the 7th fret of an E-string still plays a B note for any capo position at or below the 7th fret), and thus a performer does not need to adjust for or relearn the entire fretboard as they might with retuning. The scale length of the strings of an instrument affects the timbre of the strings, and thus the use of a capo may alter the tone of the instrument.
Musicians also use capos to bring a guitar tuned below standard up to standard tuning. Manufacturers sometimes recommend tuning a twelve-string guitar a whole-step or more below standard to offset the additional stress of the additional strings. A capo can raise it to standard tuning. However, improved manufacturing techniques have allowed many modern 12-strings to be tuned to standard pitch.
For guitar playing, some styles such as flamenco, Irish traditional music, and British and American folk music make extensive use of the capo, while it is used very rarely, if at all, in other styles such as classical and jazz playing. Many rock and roll musicians who are influenced by folk and blues, such as Richard Thompson, Ry Cooder, Ian Anderson, Steve Earle, George Harrison, Bob Dylan, Noel Gallagher, Steve Rothery, Johnny Marr, and others also use the capo. In many cases, they have extended its use past the traditional purpose of changing the key, and broken new ground, employing it in new ways. An example of using a partial capo to produce alternative sounds can be heard from guitar artist Antoine Dufour.
A strap-on capo's rubber-covered bar is held to the strings by a strap attached to either end of the bar. A strap-on capo commonly features either an elastic strap, or an adjustable fabric strap.
Modern variations on the strap-on capo include a semi-flexible plastic "strap" connected to the bar on one side and adjustable on the other side by a ratchet system. Strap-on capos differ from other capos in that most other capos contain only rigid parts, and most other styles do not wrap entirely around the neck of the instrument. This full wrap allows for fairly even pressure of the capo bar across all of the strings of the instrument. The strap-on capo is commonly a low-cost capo option, and is one of the earlier styles of capo. Because they stretch to create a tight fit, the straps on these capos can be prone to stretch-fatigue and wear.
One of the more common modern capo styles is the spring-clamp capo (sometimes termed "trigger-style" after the Dunlop trademarked Trigger capo). The most common form of this type of capo has two bars: a rubber-covered bar to barre the strings, and another that presses against the back of the neck of the instrument to hold the first bar to the strings (this second bar is commonly curved or shaped to match the contour of the back of the neck). The two bars are attached on a pivot at one end; a spring presses the bars together.
Each bar has a 'grip' attached at a right angle to the bar; the two grips, when squeezed together by the user, pull the two bars apart, allowing the user to quickly release the capo's grip, apply or adjust the capo, then release the grips, allowing the spring to pull the bars together again. The look of the grips, and the action of squeezing them is akin to a gun's trigger, leading to the name of this capo. These are the most common design referred to as "quick-release" capos.
Though other styles also use that term, the spring clamp capo, because it can be operated by one hand in one single squeezing motion, is typically the quickest capo to apply or move on the instrument; other capos can be quicker and easier to remove from the instrument. One disadvantage to the spring clamp capo is that the pressure of the spring is not adjustable. The spring applies its maximum pressure to hold the strings down, which could have an effect on the tuning of some guitars if not applied properly. These capos can typically be applied either to the treble or bass side of the instrument, depending on the player's preference. Two of the most recognizable models of spring clamp capos are manufactured by Dunlop and Kyser.
Certain manufacturers have created their own unique attempts to create the ideal capo. One of the more popular and well recognized capos is the Shubb capo. The Shubb capo is applied by holding the capo in its desired location, and closing a lever to secure the capo. The unique aspect of this capo is that the lever presses against a second arm that presses against the back of the neck of the instrument. The amount of pressure the lever exerts is adjustable by a screw so that the capo can exert the minimal amount of pressure required to hold down the strings.
This is claimed to have the least impact possible on the tuning of the instrument. The Shubb capo has the disadvantage of requiring two hands to properly apply or move, and its adjustment is more complicated than some other capos; however, because of the lever design, the capo can be removed very quickly by simply releasing the lever. This is particularly true if the capo is applied from the treble side of the instrument, which facilitates quick removal.
There are numerous other forms of capos, many of which are variations on the above-noted designs.
Though most capos are designed to raise all strings, partial capos specifically capo only some of the strings. This may appear to have a similar effect to alternate tunings, but there are differences. A common example is a capo that covers the top five strings of a guitar leaving the bass E string uncapoed. When played at the second fret, this appears to create a drop D tuning (in which the bass E string is detuned to a D) raised one full tone in pitch. In fact, these are often marketed as "drop D capos". However, the same difference applies with a drop D capo as with a regular capo; namely, only the open tuning of the strings is affected, and thus, when used at the second fret, an E chord using the D shape has the "Drop D sound" with a low E note. However, a G-shape chord can be played as well, as the fretted E string is not as affected as it would be if the string was retuned.
Partial capos are a relatively recent design. Until their creation, some innovative players used their standard capos (or altered capos) to cover only some of the strings of their instruments. The above-mentioned drop D design was previously achieved, for example, by applying a spring clamp capo to the treble side of the fretboard but leaving the bass E string uncovered. Similarly, users of the Shubb capo altered their capos by cutting off some of the rubber-covered bar's length or by altering the rubber covering to leave certain strings uncapoed.
Other common partial capo schemes include capoing the 2nd fret of the 3rd, 4th and 5th strings (producing the effect of DADGAD tuning raised two semitones), or on the 2nd fret of the 2nd, 3rd and 4th strings (open A major). Again, this creates no change of fingering above the capo.
American guitarist Dominic Frasca uses single string "mini capos", attached by drilling through the neck of his customized 10-string guitar. These are similar to the single-string "capos" many Eastern instruments use, in which the string is hooked under the head of the "nail" when one wants to capo it. This is a common capo practice during the performance of a musical piece, so that the tuning at the end of the piece will sound different from the one used at the beginning.
This is a common method of capoing the fifth string of the banjo, since the string begins at the 5th fret. Thus, it needs to be capoed individually since it is not covered by a capo on the other four strings.