A method is proposed which allows one, for any given element in a given solid phase for which experimental data on a thermodynamic vibrational quantityf(Te) are available at a temperatureTe, to calculate values of the same quantity at different temperatures and values of other thermodynamic vibrational quantities at any temperature. The quantitiesf(T) here considered are specific heat at constant volumeCv and entropyS. Assumptions on which the method rests are explicitly stated and discussed. The method was checked by comparing expected values derived from its application with available experimental data. Agreement is within two per cent for 51% of cases and within ten per cent for another 36% of all 325 considered cases.