What is the Gregorian mode?

The Gregorian mode refers to a system of scales used in Gregorian chant, which is an important aspect of Western music history. While the twelve major and minor scales are foundational to modern Western music, they are not considered Gregorian modes. Gregorian modes are derived from the system established during the medieval period, where different modes were employed to create melodies that had distinct characteristics and emotional qualities.

Gregorian chant is characterized by its use of modes that include an array of diatonic scales—specifically, the eight church modes, which consist of four authentic modes (Dorian, Phrygian, Lydian, and Mixolydian) and their plagal counterparts. Each mode imparts a different feel to the music and is not limited to the major and minor scale system that defines much of contemporary music.

Thus, the correct understanding of a Gregorian mode is more accurately aligned with the system of musical scales and characteristics unique to the chant tradition rather than the broader twelve-scale framework of major and minor scales.