Guitars with whammy bars enable players to produce vibrato manually.

Guitarists do also produce true vibrato in many different ways, including:

Ms. Troyanos, as the Queen, produced far too much vibrato to serve this music well, but Mr. Noble's troubled obsession came through the swirl of sound.

Not all instruments can produce vibrato, as some have fixed pitches which cannot be varied by sufficiently small degrees.

The method of producing vibrato on other instruments varies.

Brass instrument players may produce vibrato by gently shaking the horn which varies the pressure of the mouthpiece against the lip.

Violinists and other players of string instruments produce vibrato by moving the finger backwards and forwards on the fingerboard.

Violin students generally rely on sensations in the muscles and tendons of the arm to select and shape movements that produce better vibrato.

"This study really takes the subjectivity out of producing vibrato," he said.

Mrs. Stewart also instructs her students to keep their lips soft and flexible, articulate clearly, produce vibrato in even pulses and hit perfect pitch.