vibrato

Vibrato is a musical technique that adds warmth and expressiveness to vocal or instrumental tones. It is achieved through slight, rapid variations in pitch, creating a "tremulous effect". This technique is distinct from the fundamental vibration of an instrument, which produces the basic musical sound.123

While the term "vibrato" itself refers to pitch variation, the root concept of vibration is fundamental to all musical sound. Instruments produce musical tones through controlled periodic vibrations of strings, reeds, or air columns. These vibrations are what set the surrounding air in motion, creating the audible sound. The quality of a musical tone, its timbre, is determined by the presence and intensity of overtones, which are partial vibrations that accompany the fundamental vibration.342