  We calculate analytically quasi-normal modes of AdS Schwarzschild black holes
including first-order corrections. We consider massive scalar, gravitational
and electromagnetic perturbations. Our results are in good agreement with
numerical calculations. In the case of electromagnetic perturbations, ours is
the first calculation to provide an analytic expression for quasi-normal
frequencies, because the effective potential vanishes at zeroth order. We show
that the first-order correction is logarithmic.
