This paper investigates the application of classical PID control laws to the special case of an analog tracking system. Through step-by-step development of this tracking system, several fundamental properties of general PID control are highlighted. A broad class of circuits is shown to satisfy the PID transfer function, which leads to a discussion of performance objectives and error considerations. Once the design has been completed, the performance of the tracking circuit is analyzed in a variety of scenarios. Three examples verify the concepts presented and illustrate the advantages of PID control.