The eight church modes governed Western sacred and, for a long period, secular composition through the medieval and much of the Renaissance era, but by the sixteenth and seventeenth centuries composers had increasingly narrowed their working vocabulary toward what became the major and minor tonal system that dominates later Western classical and popular music, a shift theorists still debate in its precise causes and timing but generally trace to the growing centrality of harmonic, chord based thinking over the older melodic, mode based logic.
Two of the medieval modes, the Ionian, corresponding closely to the modern major scale, and the Aeolian, corresponding closely to natural minor, effectively absorbed most later Western composition, while the remaining modes receded into more specialized use. They never disappeared entirely: folk music traditions across Europe preserved modal melodies that never fully assimilated into major minor tonality, and twentieth century jazz and rock musicians rediscovered modes such as Dorian and Mixolydian as a deliberate alternative harmonic palette, often without direct reference to the Gregorian chant repertoire from which the names ultimately derive. Church musicians and scholars specializing in early music performance have likewise sustained direct, historically informed engagement with the original modal system, so the Gregorian modes persist today along two quite different tracks, one an active area of liturgical and scholarly practice, the other a diffuse influence absorbed into music with no conscious connection to its monastic origin.