In this paper, the transient response of a rotor subjected to a general forcing function is presented. The rotor model permits any number of in-span bearings, which include stiffness, damping, and mass properties. The excitation forces may include distributed loadings along the rotor as well as transient bearing base motion. The response is found by use of a modal analysis that incorporates the damped mode shapes. An illustrative example is presented of a rotor subjected to an initial displacement and a saw-tooth bearing base displacement.