Vibrato is the pulse or wave in a s

Vibrato is the pulse or wave in a sustained tone that gives the voice a professional sound. The ability to control your sustained tone with or without vibrato is extremely important for any vocal style. Although vibrato is a musical effect commonly taught in the study of string instruments and most wind instruments, it has rarely been explored in depth in voice training.
The following quotes, from individuals who should know better, show an amusing variety of misinformation and lack of clear knowledge concerning vibrato for singing.

"Only opera singers need vibrato."
"It's a gift from God."
"Vibrato is not pure. It distorts the sound of beautiful resonance."
"Vibrato is an undesirable effect because it causes a tremolo."
"It's an emotional reaction when you're excited about the song."
"Rock singers don't need vibrato."
Even the Harvard Dictionary of Music states that "among singers, there exists ... uncertainty as to what vibrato means" and refers to the "singer's use of it without being aware of doing so." This lack of awareness extends to some people who have said, "You can't teach vibrato" or "I plant the seed in your subconscious ... every lesson, I water the seed."