Heavy voice = no agility!, , As someone with a naturally heavy voice, riffing and vibrato have always been difficult for me to achieve., , But once I learned that in order to improve your vocal Vibrato is the slight oscillation of pitch produced when the vocal cords are balanced and relaxed, creating a warm and expressive sound. Developing a natural vibrato is a key aspect of vocal What You Should Know About Vibrato According to a Vocal Instructor Frontiers Perceived vibrato and the singing power ratio explain overall evaluations in opera singing