As part of a project to develop new electronic materials based on the coupling of electronic and structural properties in new perovskites we have been investigating the properties of Mo containing double perovskites. Previously we have investigated the cubic double perovskite Ba2LuMoO6, which is a rare example of a valence bond glass. We propose to investigate the persistence of this phase with structural distortion to a monoclinic phase by Sr substitution on the A site. The proposed muSR experiment will enable us to characterise the magnetic behaviour in key samples across the solid solution and hence investigate the sensitivity of the valence bond glass state to structural distortion.