  We present a class of holographic massive gravity models that realize a
spontaneous breaking of translational symmetry - they exhibit transverse phonon
modes whose speed relates to the elastic shear modulus according to elasticity
theory. Massive gravity theories thus emerge as versatile and convenient
theories to model generic types of translational symmetry breaking: explicit,
spontaneous and a mixture of both. The nature of the breaking is encoded in the
radial dependence of the graviton mass. As an application of the model, we
compute the temperature dependence of the shear modulus and find that it
features a glass-like melting transition.
