You have no backbone

"You hit upon what I consider one of my secrets, and that is the effect that the backbone has upon the voice.

An old Italian teacher was in the habit of saying at times to a pupil: 'You have no backbone,' meaning that she did not have the correct bodily attitude. A stooped, sagged position is destructive of good tone; whereas an erect posture—the correct holding of the backbone—enhances the power and beauty of the tone wonderfully. I have discovered just how it should be done, and the results I reach thereby are very gratifying."  —The Voice, "Sabrina Dow: An Interview with One of Boston's Leading Vocal Teachers," September 1886: 143

"Head free and straight (feel your head like a flower and the neck as its stem)." —Emi de Bidoli, Reminiscences of a Vocal Teacher, 1946: 51

"The desire to sing should straighten you up like a soldier."  —Giovanni Battista Lamperti, Vocal Wisdom: The Maxims of Giovanni Battista Lamperti, 1931

"The ear is the spine, the spine is the ear." —Alfred A. Tomatis