Since worship is primarily about offering an acceptable gift to God, I need to be certain that the gift being offered is one God will be pleased with. The music we use is examined for scriptural soundness. The lyrics of each song are carefully considered in light of the scriptures so that false teaching doesn't creep into our church. The word of God is to dwell in us in all wisdom. Music is a powerful tool to help us remember the scriptures.
Memorization is easier if it happens in association with music.
The tune will help the believer remember the passage. But music does much more than that. We are to teach and admonish one another with Psalms, hymns and spiritual songs. The singing that happens in our individual lives and in our church has the ability to communicate a powerful message to God and his people. When we think of the magnitude of responsibility that a preacher or teacher of God's word has, how can we take lightly the teaching ability music has in our lives.