<P> A chordophone is a musical instrument that makes sound by way of a vibrating string or strings stretched between two points . It is one of the four main divisions of instruments in the original Hornbostel - Sachs scheme of musical instrument classification . </P> <P> What many would call string instruments are classified as chordophones . Violins, guitars, lyres, and harps are examples . However, the word also embraces instruments that many would hesitate to call string instruments, such as the musical bow and the piano (which, although sometimes called a string instrument, is also called a keyboard instrument and a percussion instrument). </P> <P> Hornbostel - Sachs divides chordophones into two main groups: instruments without a resonator as an integral part of the instrument (which have the classification number 31, also known as simple); and instruments with such a resonator (which have the classification number 32, also known as composite). Most western instruments fall into the second group, but the piano and harpsichord fall into the first . Hornbostel and Sachs' criterion for determining which sub-group an instrument falls into is that if the resonator can be removed without destroying the instrument, then it is classified as 31 . The idea that the piano's casing, which acts as a resonator, could be removed without destroying the instrument, may seem odd, but if the action and strings of the piano were taken out of its box, it could still be played . This is not true of the violin, because the string passes over a bridge located on the resonator box, so removing the resonator would mean the strings had no tension . </P> <P> Electric string instruments often have an electromagnetic pickup that produces a signal that can be amplified . The electric guitar is the most common example, but many other chordophones use pickups--including mandolins, violins, and the overtone koto . </P>

Which group of instruments listed below contains examples of the classification chordophone