In Catholic and classical thought, music is tied to movement because it affects our bodies and thus our emotions. Likewise, music is not neutral but has an ethical quality to it because it helps form virtue in the individual in a way not immediately accessible to reason.
By movement, we ought to understand this interiorly not simple in terms or exterior body motion. The mind apprehends a truth and the will is moved to accept or reject what the mind has perceived. The will is moved by the emotions or what the tradition calls passions. When lyrics are combined with the emotional content provided by sound and music, they impress themselves more strongly upon the soul, creating not just a passing impression but leading to the formation of virtue and identity.
In this regard, liturgical music is to assist the believer in surrendering one’s self to Christ in meditation and contemplation. Understood in this context, things such as dancing or strong emotional movements that cloud the reason are foreign to the liturgy and it’s goals.
On a practical level, musicians should understand that the main goal of liturgical music is to lead to stillness and a rested, receptive, and contemplative state. The goal is not to excite the emotions towards action, but to quiet the mind to rest in the truth and beauty of who God is.
Generally speaking, strong rhythms that are associated with dance should be avoided. Likewise, strong cord progressions that are intended to excite should be limited. This does not mean, in my estimation, that all modern and contemporary Christian and Catholic music is unacceptable. If it is chosen, it should be played and arranged with the goal of the liturgy in mind.
In scripture, we can look to the example of St John the Baptist to understand all aspects of the liturgy and their relationship to Christ. Singers and musicians should conduct themselves in a way to maintain the focus on Christ. We are the voice, but Christ is the word. We prepare the way to prayer and contemplation, but must not be an obstacle to it. Christ must increase and we must decrease.