This paper presents the extension of a novel superposition method, put forth for static analysis earlier, for carrying out free vibration and bifurcation buckling studies of orthotropic rectangular plates with any combination of classical boundary conditions viz. clamped, simply supported and free edges. It is shown that use of infinite series counterparts of conventional Levy-type closed-form expressions result in a tremendous simplification of the problem without any compromise on accuracy. The complicating effects of an elastic foundation and initial stresses are also shown to be easily accounted for. Results, useful as benchmarks in future, are presented for a chosen set of cases.