Immediately while reading Chapter 1 of Vocal Technique, I had an "AHA! moment". Even as an adult choral student, I have ignored my choir director's demands to stand up straight, despite being aware of the benefits proper posture could have on my sound. Feeling I was too tired to stand up straight, I thought of it as a chore, not realizing that practicing proper spinal alignment would reduce fatigue. 

David makes the invaluable point here that fully understanding the value of a balanced posture will encourage students to comply. This is our duty as educators.

I disagree, however, with David's method of creating alignment. She says, "align your body so that an imaginary straight line passes from the top of the head". Telling students so stand up straight or stand in a straight line can cause unnecessary tension and pain just as hunching over can. In my opinion the ideal stance is about feeling balance which is slightly different for everybody and the spine has a natural slight curve. I do though, understand that a singing stance involves a slightly elevated sternum which requires an adjustment to every-day standing posture.

Davids, J., & LaTour, S. A. (2012). Vocal technique: A guide for conductors, teachers, and singers.

Food for thought: Body Alignment Methods for Choral Teaching

http://www.choralnet.org/2013/07/vocal-advantage-body-alignment-part-3-by-dina-else/

Music and Memory

http://www.bulletproofmusician.com/why-the-progress-in-the-practice-room-seems-to-disappear-overnight/