Many singers who study with me who sing styles of music not associated with a full vibrato wonder why I insist upon developing a smooth steady vibrato in their lessons. Why bother if they aren’t every going to use it? This is an excellent question. I can’t remember who said it, but I love the analogy of vibrato being like the idle of the car. If the car is idling too quickly or too slowly you know something is wrong.
A good vibrato comes at a rate of approximately 6 to 8 beats per second. The actual cause of vibrato is a point of controversy among many vocal professionals, but we do all tend to agree that it is the result of a balance of air flow and cord closure in a vocal environment where the extrinsic laryngeal muscles are in a neutral posture. As I state often, when a singer is vocalizing, the style is completely stripped from the voice as we are building pure technique. Good vocalizing is essential for achieving and maintaining optimal vocal health and longevity.
If a singer is engaged in singing styles that do not use vibrato, this means that the style of singing is farther away from vocal balance than styles which use vibrato. It is imperative that these singers have a clear sense of what balanced vocal production is in order to know how far they can healthfully take their styling before getting into danger.
If a singer is needing to sing in a “vibrato-free” manner, I first want them to develop a balanced singing technique where the vibrato is spinning freely at a healthy rate. Then, rather than “eliminating” vibrato from the voice, I prefer that we begin to reduce vibrato to the point that it is almost imperceptible. The difference in the presence of overtone frequencies and intensity of sound between a voice with vibrato and one with a straight tone is quite stark. By reducing vibrato rather than eliminating it, a singer will maintain a healthy voice with much more resonance and power than a singer who strains to sustain pitches on a straight, flat tone.