Guitar chord in the abstract musical-theory of chords for all instruments. For example, in the guitar (like other stringed instruments but unlike the piano), open-string notes are not fretted and so require less hand-motion. Thus chords that contain open notes are more easily played and hence more frequently played in popular music, such as folk music. Many of the most popular tunings—standard tuning, open tunings, and new standard tuning—are rich in the open notes used by popular chords. Open tunings allow major triads to be played by barring one fret with only one finger, using the finger like a capo. On guitars
Tuning mechanisms for stringed instruments pattern on a peg shaft interferes with this action, pegs occasionally require refitting, a specialized job which amounts to reshaping both pegs and holes to a smooth circular conical taper. Tapered tuning pins are similar, but must be turned with a tuning tool, usually called a tuning key, tuning lever, or tuning wrench. Historically, pins were also tapered (see image of bone peg, right), but they are now generally threaded, instead (see below). Tapered pegs are a simple, ancient design, common in many musical traditions. Tapered pegs are common on classical Indian instruments such as the sitar, the Saraswati veena,