A simple tight-binding model is for a quantitative study of hybridisation effects in transition-metal-polyvalent-metal (T-P) alloys. The model is not an ab initio calculation but it requires only the data on elemental properties of pure metal constituents which are readily available in the literature. The Cluster-Bethe lattice method is used to calculate the electronic density of states and thermodynamic properties of (Fe, Co, Ni)_xAl_1-x and Co_xGa_1-x alloys. It is shown that the electronic density of states around equiatomic composition is characterised by the occurrence of a pseudogap near the top of the d band. The authors use the model to discuss the essential features of some anomalous electronic and thermodynamic properties of T-P alloys.