The extent of the variation in pitch in vibrato is down to the performer, but does not usually exceed a semitone either way from the note itself. The effect is intended to add warmth to a note. A helpful side effect is that it can help to disguise bad tuning.
A precursor to vibrato was the trillo (not to be confused with a trill), used in vocal music in the early 17th century, where a singer would rapidly repeat the same note on one syllable. The effect was much more strident than that of vibrato, and is compared by some to the bleating of a sheep.
Not all instruments can produce vibrato, as some have fixed pitches which can not be varied by sufficiently small degrees. Most percussion instruments are examples of this, as is the piano. Some types of organ however, can produce the effect by altering the pressure of the air passing through the pipes, or by various mechanical devices (see the Hammond or Wurlitzer Organs[?] for example).
Some instruments are played with constant, mechanical vibrato, notably the vibraphone and the Leslie speaker[?] used by many electric organists. Soul singer Aaron Neville[?] sings with vibrato, having been originally inspired by yodeling[?].
The method of producing vibrato on other instruments varies. On string instruments, for example, the finger used to stop the string can be wobbled on the fingerboard, or actually moved up and down the string for a wider vibrato.
In pop music the effect is sometimes heard on the guitar and some, but not all singers, use it (in some pop ballads, the vibrato can be so wide as to be a pronounced wobble). The use of vibrato in some folk musics is rare, or at least less pronounced than in other forms of music, although in Eastern European gypsy music, for example, it can be very wide.
Most jazz players through the 20th century and up to the present day have used vibrato more or less continuously. From around the 1950s, however, some players in more avant garde styles, many following the example of Miles Davis, began to use it more selectively, playing without vibrato as a rule. Davis, however, frequently used a mute, which also alters the tone of the instrument.
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 the producer of a children's jazz album to demonstrate the difference between the two. Despite his otherwise exemplary technique, he was unable to play without vibrato.
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 (1960), advised violinists to practice 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.
The use of vibrato in classical music is a matter of some contention. For much of the 20th century it was used almost continuously in the performance of pieces from all eras from the baroque onwards, especially by singers and string players. This began to change somewhat towards the end of the century, with the rise of historically informed performances, and as one travels further back in music history, the use of vibrato appears to become increasingly rarer.
Vocal music of the renaissance is almost never sung with vibrato as a rule, and it seems unlikely it ever was. There are only a few texts from the period on vocal production, but they all condemn the use of vibrato.
Leopold Mozart's Versuch einer gründlichen Violinschule (1756) provides an indication of the state of vibrato in string playing at the end of the baroque period. In it, he concedes that "Performers there are who tremble consistently on each note as if they had the palsy", but condemns the practice, suggesting instead that vibrato should be used only on sustained notes and at the ends of phrases.
In wind playing too, it seems that vibrato in music up to the 19th century was seen as an ornament to be used selectively. Martin Agricola writing in his Musica instrumentalis deudch (1529) writes of vibrato in this way. Occasionally, composers up to the baroque period indicated vibrato with a wavy line in the sheet music, which strongly suggests it was not desired for the rest of the piece.
It was towards the end of the 19th century that the use of vibrato in classical music began to be more normal. This increase in the popularity of vibrato was helped by changes in the design of string instruments, specifically the invention of the chin rest on the violin and viola, and of the spike on the cello. These inventions made wider and more sustained vibrato possible.
Music by late romantic composers such as Richard Wagner and Johannes Brahms is now played with a fairly continuous vibrato. However, some musicians specialising in historically informed performances such as the conductor Roger Norrington[?] argue that it is unlikely that Brahms, Wagner, and their contemporaries, would have expected it to be played in this way. This is a somewhat controversial view, although Arnold Schoenberg, a considerably later composer, seems to have disliked vibrato as well, likening it to the bleating of a goat.
The growth of vibrato in 20th century orchestral playing has been traced by Norrington by studying early recordings. He claims that vibrato in the earliest recordings in used only selectively, as an expressive device; the Berlin Philharmonic Orchestra were not recorded using vibrato comparable to modern vibrato until 1935, and the Vienna Philharmonic Orchestra not until 1940. French orchestra seem to have played with continuous vibrato somewhat earlier, from the 1920s.
Despite this, the use of indiscriminate vibrato in late romantic music goes largely uncontested (although performances of Ludwig van Beethoven with limited vibrato are now not uncommon). Many people take the view that even though it may not be what the composer envisioned, vibrato adds an emotional depth which improves the sound of the music. Others feel that the leaner sound of vibratoless playing is preferable.
In 20th century classical music, written at a time when the use of vibrato was widespread, there is sometimes a specific instruction not to use it (in some of the string quartets of Bela Bartok for example). Furthermore, some modern classical composers, especially minimalist composers, are against the use of vibrato at all times.
See also: wah-wah