This course aims to develop a comprehensive understanding of the microscopic origins of lattice and electronic properties in solids. Students will study lattice vibrations and phonons, explore lattice Green’s functions and local modes, and analyze how these affect the dynamical behavior of crystals. The course introduces the theory of electron energy bands and density of states calculations, providing the foundation for understanding the electronic structure of materials. Applications to the optical and transport properties of solids will be emphasized, bridging fundamental theory with experimentally observable phenomena in condensed matter physics.