Gregorium is a contemporary revisitation of Liturgic music and its evolution in time, where the sounds are generated from a heavy manipulation of Gregorian chants and Trecento Madrigals. The work is composed of three pieces with the first being an interpretation of the monodic Gregorian style, the second being a polyphonic non monodic melody and the third one being a more complex and articulated melody representing the Italian Trecento Madrigals of the 14th Century. The transition is hereby represented by the evolution in the articulations of melodies and sounds which drives the listener through different stages of musical evolution and therefore requires different listening methods.