As discussed in , the white-noise excitation used in the KS digitar and EKS algorithms can be interpreted physically as a random initial displacement and velocity for each string element (spatial sample), and the resulting string vibration decays exponentially, corresponding to a linear string model. This type of model works well for plucked and struck strings, particularly a variety of lively clavier-type instruments. However, to model a real acoustic stringed instrument, such as a classical guitar or piano, we need to model the body resonator (guitar body, soundboard, etc.).
Note that solid-body electric guitars, such as the Les Paul or Stratocaster, do not need a resonator model, because their string vibrations are measured directly by magnetic pickups, and body resonances (which are minimized in solid-body design and construction) have only a small effect on the pickup signal. Therefore, all we really need for these instruments, beyond our string model, is guitar effects, such as distortion, and a good amp model, because electric guitar players classically achieve their ultimate sound in conjunction with the nonlinear operation of a good guitar amp (preferably a tube amp, as of this writing).