In this work we develop an educational software about normal modes in a chain of coupled oscillators. The software simulates the dynamical evolution of the system allowing to choose initial conditions in cartesian coordinates or in normal modes. We focus on the effect of decoupling the system of differential equations (transition from cartesian coordinates to normal modes) in the qualitative dynamics of the oscillators, either in the quasiperiodic or in the periodic regime. The purpose is to give the student some insights about the meaning of the normal modes.