The guitar is a fretted musical instrument that usually has six strings. It is pressed against the player’s body and is played by playing or plucking the strings with the dominant hand while pressing the selected strings against the frets with the fingers of the opposite hand. A pick or separate picks can also be used to strike the strings.
The sound of the guitar is either projected acoustically using a resonant chamber on the instrument or amplified by an electronic pickup and amplifier. The guitar is classified as a chordophone, which means that the sound is produced by a vibrating string stretched between two fixed points. Historically, the guitar was made of wood with catgut strings.
Steel guitar strings were introduced towards the end of the nineteenth century in the United States; Nylon strings appeared in the 1940s. Ancestors of the guitar include the gittern, the vihuela, the Renaissance four-course guitar, and the five-course baroque guitar, which contributed to the development of the modern six-string instrument.