Breathing is one internal function that the conscious mind can control with comparative ease. The effect of controlled breathing is almost like communication with all conscious parts of one's being saying to them, "Simmer down and listen; there is something beyond the turmoil". It is communication in action that often works when words merely go in one ear and out the other, not even changing the cognitive mind. In essence, the effect is to turn all the elements of our will toward stillness and waiting.
As I was listening I thought about being in conversation with God, and I was struck by how much Bach's Fugue in G-Minor mirrors my relationship with God. When I first began conversing with God, it was very simple. In reply, God did not repeat my melody but responded in a harmonic way, just as Bach has his instruments do. Over time, our conversation -- the Divine and mine -- has built in richness, complexity, depth and beauty, like the fugue builds. Ebb and flow occur in the dynamics of both music and my communication with God, but my soul is constantly stirred by the heartbreaking beauty of what I hear and what I know.