The present work was focused on formalizing a mathematical description of aerodynamic forcing mechanisms relevant to compressor blade vibration. The hypothesis was that the functional form of the aerodynamic forcing functions could categorize the various aerodynamic forcing mechanisms. Based on this hypothesis, the multitude of aerodynamic forcing mechanisms relevant to compressor aeromechanics was divided into three categories: 1) external forcing, 2) blade-row aerodynamic forcing, and 3) motion-dependent forcing. Modal forcing models for each category were presented, including a novel model for rotating stall effects. Simulations for each category demonstrated distinct and unique temporal characteristics of the response to different aerodynamic forcing mechanisms. Good agreement with experimental data supports using these temporal characteristics to identify the physical forcing mechanisms present in measured blade vibration data.