It is shown that the dynamical evolution of perturbations on a static space
time is governed by a standard pulsation equation for the extrinsic curvatu
re tensor. The centerpiece of the pulsation equation is a wave operator who
se spatial part is manifestly self-adjoint. In contrast to metric formulati
ons, the curvature-based approach to perturbation theory generalizes in a n
atural way to self-gravitating matter fields, including non-Abelian gauge f
ields and perfect fluids. As an example, the pulsation equations for self-g
ravitating, non-Abelian gauge fields are explicitly shown to be symmetric.