The statistical properties of a classical field propagating through a randomly inhomogeneous medium are analysed by a method in which the random medium is described by the two-point (bilocal) correlation function of its random characteristic,e.g., refractive index, potential, convective velocity, etc. A scheme of diagrams is introduced to classify the types of interaction between the propagating field and the random background. Equations for the one- and two-point fields are given, and the wave dispersion and attenuation they imply are discussed. The analysis is very similar to the Tamm-Dancoff theory of one- and two-nucleon propagators with virtual meson dressing and interaction, with the correlation function here playing the role of the meson field. A number of results obtained through the use of the method are described and various projected applications are cited.