The main motivation is to investigate meson properties in the quark model to understand the model applicability and generate possible improvements. Certain modifications to the model are suggested which have been inspired by fundamental QCD properties (such as running coupling or spin dependence of strong interactions). These modifications expand the limits of applicability of the constituent quark model and illustrate its weaknesses and strengths. The meson properties studied include meson spectra, decay constants, electromagnetic and electroweak form-factors and radiative transitions. The results are compared to the experimental data, lattice gauge theory calculations and other approaches
