This chapter introduces a few applications of computational vibrational spectroscopy other than those described in preceding chapters. The aqueous solutions with various solutes such as salts and biomolecules are intriguing targets of the quantum/classical mixed approach as well as molecular dynamics simulations. Vibrational spectroscopy is a unique probe for these solutions, enabling one to obtain molecular-level insight into hydration structure and dynamics. In particular, the excellent performance of a recently developed force field for salts is demonstrated from the viewpoint of vibrational spectroscopy. Moreover, the experimental as well as computational vibrational spectra of liquid alcohols in addition to their universal vibrational spectroscopic maps developed recently are also presented. In addition, the current situation of the quantum/classical mixed approach to the amide I vibration of proteins is briefly introduced.