Vibrato

Vibrato (Italian, from past participle of 'vibrare', to vibrate) is a musical effect consisting of a regular, pulsating change of pitch. It is used to add expression to vocal and instrumental music. Vibrato is typically characterised in terms of two factors: the amount of pitch variation ('extent of vibrato') and the speed with which the pitch is varied ('rate of vibrato').This combination is relatively stable in the most beautiful voices. An important feature is that the partial functions can appear during the song as 'accents': In the context of the presentation expressive wave dominates respirativa, lyrical character, but in an accelerated, or glottis wave, hard feature heroic, but in a slow way. Vibrato (Italian, from past participle of 'vibrare', to vibrate) is a musical effect consisting of a regular, pulsating change of pitch. It is used to add expression to vocal and instrumental music. Vibrato is typically characterised in terms of two factors: the amount of pitch variation ('extent of vibrato') and the speed with which the pitch is varied ('rate of vibrato'). In singing it can occur spontaneously through variations in the larynx. The vibrato of a string instrument and wind instrument is an imitation of that vocal function. The terms vibrato and tremolo are sometimes incorrectly used interchangeably, although (in the classical world) they are properly defined as separate effects with vibrato defined as a periodic variation in the pitch (frequency) of a musical note, and tremolo as a fast repetition of the same note (usually a semiquaver) in order to produce the audible effect of a longer note, especially on instruments which do not have the ability of producing long sustained notes, such as the guitar. In practice, it is difficult for a singer or musical instrument player to achieve a pure vibrato or tremolo (where only the pitch or only the volume is varied), and variations in both pitch and volume will often be achieved at the same time. Electronic manipulation or generation of signals makes it easier to achieve or demonstrate pure tremolo or vibrato. In the world of electric guitar and record production vibrato retains the same meaning as in the classical world (a periodic variation in pitch) but tremolo describes a periodic variation in volume usually achieved using outboard effects units. A Leslie speaker (best known through its historical and popular association with the Hammond organ) creates vibrato as a byproduct of tremolo production. As a Leslie speaker is moved by the rotating mechanism on which it is mounted, it moves closer to or farther away from any given object (such as a listener's ears) not also mounted on the mechanism. Because amplitude varies directly with sound pressure (A = k1P) and sound pressure varies directly with distance (P = k2d), such that amplitude also varies directly with distance (A = k1(k2d) = k1k2d), the amplitude of the sound as perceived by the listener will be greatest when the speaker is at the point in its rotation closest to the listener and least when the speaker is farthest away. Because the speaker is constantly moving either toward or away from the listener, however, the mechanism's rotation is constantly affecting the listener-perceived sound's wavelength by either 'stretching' the wave (increasing wavelength) or 'squeezing' it (decreasing wavelength) — and because frequency, i.e., pitch, is inversely proportional to wavelength, such that increasing wavelength decreases frequency and vice versa, any listener for whom the speaker's motion changes the sound's perceived amplitude (i.e., any listener whose distance from the speaker is changing) must also perceive a change in frequency. However, the size of this effect is likely to be tiny compared against the tremolo effect since the distance oscillation is very small. The use of vibrato is intended to add warmth to a note. In the case of many string instruments the sound emitted is strongly directional, particularly at high frequencies, and the slight variations in pitch typical of vibrato playing can cause large changes in the directional patterns of the radiated sound. This can add a shimmer to the sound; with a well-made instrument it may also help a solo player to be heard more clearly when playing with a large orchestra. This directional effect is intended to interact with the room acoustics to add interest to the sound, in much the same way as an acoustic guitarist may swing the box around on a final sustain, or the rotating baffle of a Leslie speaker will spin the sound around the room. The rate and extent of the variation in pitch during vibrato is controlled by the performer. The extent of vibrato for solo singers is usually less than a semitone (100 cents) either side of the note, while singers in a choir typically use narrower vibrato with an extent of less than a tenth of a semitone (10 cents) either side. Wind and bowed instruments generally use vibratos with an extent of less than half a semitone either side. Vibrato is sometimes thought of as an effect added onto the note itself, but in some cases it is so fully a part of the style of the music that it can be very difficult for some performers to play without it. The jazz tenor sax player Coleman Hawkins found he had this difficulty when requested to play a passage both with and without vibrato by Leonard Bernstein when producing his record album 'What is Jazz' to demonstrate the difference between the two. Despite his technique, he was unable to play without vibrato. The featured saxophonist in Benny Goodman's Orchestra, George Auld, was brought in to play the part. Many classical musicians, especially singers and string players, have a similar problem. The violinist and teacher Leopold Auer, writing in his book Violin Playing as I Teach It (1920), advised violinists to practise playing completely without vibrato, and to stop playing for a few minutes as soon as they noticed themselves playing with vibrato in order for them to gain complete control over their technique.