My lovely friend and Ashtangi – Cyndi Laird, Supta Kurmasana – a most challenging pose for ‘free breathing’. Photo from www.ashtanga4life.com
”Asana practice should be a harmonious experience, never a struggle. The manner of breathing into a wind instrument — a flute, for instance — can create either a grating screech or a melodious song. The body, too, is an instrument. If used skillfully, as in the unison of movement and breath, the resulting posture is a useful and harmonious experience. When performed with the graceful orchestration of all its parts, asana can become a music of the body, breath, and mind. Such music moves everything it touches.”
~A.G. Mohan
Art Of Practice 