Plucked string instruments are not a category in the Sachs - Hornbostel classification , as some of them are simple chordophones .
Others are composite ( depending on whether the resonator is the removable part of the instrument ) .
Plucked string instruments are not a category in the Sachs - Hornbostel classification , as some of them are simple chordophones and others are composite ( depending on whether the resonator is the removable part of the instrument ) .