Comment: Here, Cornelius is working the voice to get a fuller sound in the middle, so it matches the top of the voice.

Quote: Briefly stated, the vocal pattern to be sought after should include full-bodied low tones which gradually increase in power as the scale is ascended while, in addition, the performer should possess an absolute control over changes of dynamics. When the technique fails to meet these requirements it is faulty, as either the registers lack development and are out of balance or the vowels are impure. (Bel Canto: Principles and Practices)