Comment: A vibrato starting to come through with a much more musical and free sound.

Quote: Because it is  a reflection of correct vocal technique, I.E., reflexive organic activities based upon an innate functional logic, the vibrato awakens and gains contact with those instinctual processes without which one could not be a singer. The vibrato, therefore, is an indispensable adjunct of a correct vocal technique. (A Dictionary of Vocal Terminology)