A great irony of the modern church is the increasing use of mindless repetition. Sometimes we are asked to sing a word such as "holy" 10-15 times in a row. This seems to be either an influx of mysticism or eastern religion into the Christian Church. Worship is base on truth. While there is truth in the words sung the mindless repetition of these words ceases to be content based.
Why do we wish to abandon content in worship? I cannot understand the desire to separate worship from Theology. Seeking to worship the living God with an empty mind makes little sense.
Worship has and always should be based on truth (i.e. facts and statements). The main form of worship is the sermon were statements of truth are hopefully expounded. The Bible itself is a collection of truth: statements about God, statements about man, God's will for the world and true histories of mans activities in the world.
The Lord's Supper is highly filled with content. The scriptures have a great deal of teaching on the Holy Supper and it is not wise to separate the teaching of Scripture from the Sacrament.
The early church primarily sung the Psalms from the Bible. The Psalms are theologically rich and the repetition in the psalm is deeply significant and not mindless. There are many great hymns which are not based on the psalms which I have no issue with if they contain the truth found in scriptures. What I have issue wish is music that does not wish to worship God both in spirit and in truth - mindless repetition is not a faithful attempt to worship the Lord in truth.
Prayer at times is also entering this mindless mode. Many prayers become formulas. We could simply copy the prayer exactly if we knew the template and plug in X, Y, and Z.
The reality is that prayer is a conversation. We are talking to God.
Hopefully we do not talk to people we know according to formulas. We should also ideally not talk to God as if reciting a formula.
A lot of people are afraid to open their hearts to God because they feel they might say something wrong. A better perspective is to simply open ones heart to God.
God knows our heart and we are already forgive. We should simply speak plainly to him and realize we are forgiven and is better to actually speak to God as we feel rather than to recite a formula.