BYZANTINE music is not excessively pleasant to the ear, but just pleasant enough to serve its purpose and not harm the essential part of the hymns, which is the words.
When ecclesiastical music becomes excessively pleasant, the soul attaches herself to it and loses compunction and repentance.
Fr George Metallinos, in “The Organ and Orthodox Spirituality”. Source.
O Give thanks unto the Lord, for he is good:
for his mercy endureth for ever (Ps 135)
St Nektarios, Bishop of Pentapolis and Wonderworker of Aegina, explained why our focus should be on sober attention rather than soaring emotion or excited imagination.
GOD reveals Himself to the humble, who live in accordance with virtue.
Those who take up the wings of the imagination attempt the flight of Ikaros and have same end. Those who harbor fantasies do not pray; for he that prays lifts his mind and heart towards God, whereas he that turns to fantasies diverts himself.
Those who are addicted to the imagination have withdrawn from God’s grace and from the realm of Divine revelation. They have abandoned the heart in which grace is revealed and have surrendered themselves to the imagination, which is devoid of all grace.
It is only the heart that receives knowledge about things that are not apprehended by the senses, because God, Who dwells and moves within it, speaks within it and reveals to it the substance of things hoped for.
Seek God daily. But seek Him in your heart, not outside it.
And when you find Him, stand with fear and trembling, like the Cherubim and the Seraphim, for your heart has become a throne of God.
But in order to find God, become humble as dust before the Lord, for the Lord abhors the proud, whereas He visits those that are humble in heart, wherefore He says: “To whom will I look, but to him that is meek and humble in heart?”
O GIVE thanks unto the LORD; for he is good: for his mercy endureth for ever.
O give thanks unto the God of gods: for his mercy endureth for ever.
O give thanks to the Lord of lords: for his mercy endureth for ever.
To him who alone hath wrought great wonders: for his mercy endureth for ever. […]
WHO remembered us in our low estate: for his mercy endureth for ever:
And hath redeemed us from our enemies: for his mercy endureth for ever.
Who giveth food to all flesh: for his mercy endureth for ever.
O give thanks unto the God of heaven: for his mercy endureth for ever.
Psalm 135:1-4, 23-26.
You might also be interested in the essay Adaptation, from St Anthony’s Monastery (AZ) Divine Music project.