This third edition builds on the introduction of spectral analysis as a means of investigating wave propagation and transient oscillations in structures. Each chapter of the textbook has been revised, updated and augmented with new material, such as a modified treatment of the curved plate and cylinder problem that yields a relatively simple but accurate spectral analysis. Finite element methods are now integrated into the spectral analyses to gain further insights into the high-frequency problems. In addition, a completely new chapter has been added that deals with waves in periodic and discretized structures. Examples for phononic materials meta-materials as well as genuine atomic systems are given.