  The aim of this paper is to analyze a mixed discontinuous Galerkin
discretization of the time-harmonic elasticity problem. The symmetry of the
Cauchy stress tensor is imposed weakly, as in the traditional dual-mixed
setting. We show that the discontinuous Galerkin scheme is well-posed and
uniformly stable with respect to the mesh parameter $h$ and the Lam\'e
coefficient $\lambda$. We also derive optimal a-priori error bounds in the
energy norm. Several numerical tests are presented in order to illustrate the
performance of the method and confirm the theoretical results.
