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
Polyphony and monophony in instruments (however, the keyboard instruments can have other effects considered non-producible by neither guitar or violin). Both of these can be seen in many music by Niccolò Paganini. Some non-mainstream classical instruments include strings which are fretted and plucked like those on a guitar, plus secondary strings which resonate and provide reverberation on a few key notes. When playing a single note, it is technically not polyphony, but it can be used to simulate polyphony. However, when playing multiple notes, it is physically polyphony. The electric guitar, just like the classical guitar, is polyphonic, as are various guitar derivatives (including the