In old Spain, capos called 'cejillas' or 'cejuelas' were used. These were small blocks of wood with a tuning-type peg in the top. A cord went from the peg around the back of the guitar's neck back to the peg, which was turned to tighten the block down onto the fret board. Obviously it took time to change its position. This was acceptable in pre-19th century music, when modulation of tonic keys within a musical piece was very unusual. These simple wooden capos are still used for traditional Flamenco.
Probably soon after rubber was discovered in the Amazon jungle, a capo composed of a rigid barre with an elastic strap was invented. Unhooking the strap, shifting to another position and hooking again still involved both hands, but was much faster than the old cejuela. In the mid-20th century these were called Russell capos, and were the most popular variety for a long time. Very simple and cheap, yet effective, they are still produced by Dunlop.
The word 'capodastro' originates in this era, a variation on the Italian word 'capotasti' - meaning 'top of the frets'.
Another popular capo of that era was the Hamilton, which was tightened to the guitar's neck with a screw. Even slower to change positions, yet precise. This vintage type is also still in production.
Beginning about 50 years ago, a variety of clamping mechanisms were invented using steel torsion-springs rather than elastic rubber. These clamped capos allowed faster position change with just a single hand. The oldest basic varieties are the above-the-fretboard grip (Kyser) and the behind-the-neck 'Trigger' grip (Dunlop). The disadvantage is that all the compressive force comes from one side, so it must be very tight. This may affect tuning.
The Shubb capo has no springs or elastics, but uses its geometry to allow clamping to the neck, and also has a screw for fine adjustments of the compression of the strings down onto the fret-board.
Newer, more compact springed C-clamp designs are produced by G7th, Fender, PlanetWaves, and Thalia, among others. Many of these new types allow fine-tuning of the compression with dialable screws, clutches, or ratchets. A variety of other specialized designs have also come to production.
Beside all the fixed-position capos described above, there are three capos which can be repositioned without removing or loosening them from the neck. They are the QuickDraw sliding capo (a spin-off of the old Russell), and the rolling capos from Glider and 6to Dedo. These three are the fastest of all capos to change position. Indeed, the 6to Dedo can be repositioned without even momentarily changing the fingering of the fretting hand.
Partial capos are also available that push down a selection of strings. To know how to use these, one should know about alternative guitar tunings. The ultimate partial capo is the SpiderCapo, that lets you set each string either pressed down or left open as you wish.
To learn more capo basics, go back to our Home page.
To select your favorite capo, go to our Descriptions page.
For your interest, a thorough history of the capodastro can be found at Anders Sterner's online capo museum. Reading his experienced advice on capo use is very worthwhile. http://www.sternercapo.se/capomuseum/