Why do we chant the Yoga Sutra of Maharishi Patanjali? When we write things out and work with the written word, we are dealing with external forms. The written form is the grossest level of interpretation of oral traditions. When we chant we use our vocal apparatus to produce the sound. The process brings us into the eternal NOW. When we write, a long lapse of time can pass between the time of writing and our re-reading. When we chant, the action brings us in the present moment. The process of chanting demands full attention, at least on the physical level. There is also the question of resonance. Chanting evokes and invokes resonance in letters and words. All mantra can be chanted in three forms, the vachika form(chanting externally, uttering sound) is the between, and the likita (writing) is the grossest. The subtlest way to approach the sutra would be to chant them at the level of the mind. Yet, this requires full knowledge of what one is doing. It follows that when we chant we are in the NOW, we are vibrating, and we know what we are uttering so that when we move to the subtlest plane and we chant without uttering sound, in our mind, we are as close as possible to the most perfect sound.