A generalized Fourier optics approach is employed to describe hologram recording and reconstruction in volume media. A compact expression is derived, which is suitable for the treatment of complicated optical signals propagated by arbitrary optical systems. This is in contrast to the existing literature on volume holography that is mainly focused on the derivation of high diffraction efficiency in relatively simple configurations. It is demonstrated that the traditionally accepted Bragg selectivity can be obtained as a first approximation of much more general selectivity, a generalized Bragg selectivity, that describes the deterioration of the hologram reconstruction quality as a function of the deviations from the recording configuration. As a case study, a few simple situations are analyzed in detail and an old experimental result is explained theoretically.