There are eight modes within chant, each producing a different mood. Every chant uses only one mode that does not change within the entire melody. The modes are essential for producing the mysterious melodies within chant and are very different from modern tones. They come from ancient modes used by the Hebrews in the temple and formulated by the Greeks, around 3000 years ago. The ancient philosophers saw each mode as producing a different effect on the one listening to the song. Some modes produce positive effects on the listener of the chant and others sorrowful effects, either lifting the soul into heaven or calling to mind some human event.
This is where the ancient chants differ from modern tones. The highest aim in the chant was an intelligent use of the mode to express an intelligent statement. This entails the use of the intellect. Unlike modern base rythms and beats, which mimick the rythms of the body, the chants appealed to what is most admirable in humans, the intellect. Needless to say, it seems to be a higher form of music than modern music.
Monks add the heavenly aspect to chant. Their encounters with God have added a supernatural effect on chant that is found in no other song. Monks alone add this quality to chanting. Their song is a channel that heaven uses to reach the souls of humans, because the souls of monks are open to divine inspiration. Listening to their chant is an encounter with the angels. The monks' whole goal is to offer to God what is highest within himself. Music and words being mankind's most beautiful art, the monks save it all for the worship of God in the holy liturgy.
The ancient tradition is that monks learned chant from the angels themselves. While deep in prayer, the monks could never express the divine realities as they experienced them. Inspired by grace, they prayed that the angels themselves would teach the monks how to express to others the secrets of contemplation. At this they heard the angels chanting in the most glorious other worldly tones. The souls of the monks were caught up into the song of the angels and instinctively joined into the chant.
Their chant still echoes the singing of the angels. The souls of the monks renew their song and spread throughout the world the heavenly chant. Listen to these monks chant. Their voices spread peace with every word and reflect the angelic song.