(It., from Lat. vibrare: ‘to shake’).
A regular fluctuation of pitch or intensity (or both), either more or less pronounced and more or less rapid. The Italian term ‘tremolo’ is also occasionally used for vocal vibrato. Terminology used in music was not standardized until the 20th century; earlier terms, primarily applied to vocal vibrato, include: flattement, flatté, balancement, balancé, plainte, langueur, verre cassé; tremolo, tremolo sforzato, ardire, trilletto; Bebung, Schwebung; and sweetening, depending on the effect wanted or technique used. Terminological uncertainties arise because vibrato is regarded not as a single ornament but rather as a complex of ‘quivering’ ornaments which might be modified in performance depending on the desired expression or the emotion to be aroused. Neither intensity nor tempo, therefore, can be clearly determined, and many Baroque or Classical kinds of vibrato are only distantly related to our present concept. ‘Wobble’ (exaggerated, slow or irregular vibration of the singing voice) is a technical fault, and not to be regarded as vibrato.
Vibrato as a device can be found throughout Western music with descriptions dating from early medieval sources to the present day, but the techniques have varied. Historical descriptions are often vague and do not make clear how the vibrato was actually produced, but it seems always to have been accepted as an ornament until the first quarter of the 20th century, when its continuous use gradually became the norm.
On string instruments vibrato is produced by moving the finger on the string backwards and forwards, aided by the wrist and sometimes by the forearm. On fretted string instruments such as viols ‘two-finger’ vibrato (also known as the close shake or langueur) was used, the first finger being placed firmly on the string and the second making a trilling movement near to it, thus creating an undulation of about an eighth- to a quarter-tone. Only with the little finger was a ‘normal’ vibrato comparable to modern practice allowed as a substitute for the usual technique (sources in England and France agree on the subject). German violin sources of the late 17th century and the 18th also describe a vibrato produced without the usual rocking movements of the finger; here too, a slight beating of the string in a trill-like movement without altogether leaving it is described (e.g. Printz, 1676, or Petri, who suggests combining this technique with the inward and outward movement of the finger, thus actually describing the changes in finger pressure explained by Tartini and Leopold Mozart in their tutors). Two-finger vibrato on the violin (the ‘gypsy trill’) is not mentioned explicitly. One unclear passage in Mersenne could point to it, but more likely a beat (mordent) is meant; Tartini refers to it in passing. Rocking of the fingers has always been the usual technique for producing vibrato on string instruments of the violin family. The amount of wrist or arm movement differs according to different schools of violin playing.
On plucked instruments the same device (known variously in history as tremolo, tremolo sforzato, verre cassé, soupir, mordant) is found. The lower strings of the lute, however, demand a stronger movement: here the string is pulled back and forth (indicated by the same symbol as the mordent; on higher strings the vibrato is indicated by <).
On wind instruments during the 17th and 18th centuries vibrato was normally produced by a trill-like movement (usually made with stiff fingers) over a hole some distance from the ones covered, thus producing a very slight fluctuation in pitch. Breath vibrato is described early in the 16th century (Agricola, Ganassi) but seems to have been abandoned because of its bad effect on breathing technique. The Flattement (or sweetening, Bebung or Klopfen) was in use throughout the 17th and 18th centuries and at the beginning of the 19th. There was some experimenting in the second half of the 18th century, resulting, for example, in Lusse’s rolling of the flute to produce a vibrato by slight changes of the embouchure. When all these forms as well as the written-out measured vibrato (see below) became obsolete, there seems to have been a period with little or no vibrato on wind instruments; only in the 20th century did ‘breath’ (diaphragm) vibrato become generally accepted as the norm, even if it is still not universally used on all wind instruments (e.g. clarinets, horns, Viennese oboes).
Vocal vibrato is regarded as standard if the voice is well supported; during the 16th to 18th centuries it was supposed to be small and was considered virtually non-existent. It is impossible to establish whether ‘vibrato-free production’ (described at least until the end of the 19th century) denotes a sound entirely without vibrato in the modern sense; statements that the singing voice differs from the speaking voice in that it contains an almost inaudible vibrato rather suggest that it does not (see Dodart, 1706). Some Baroque treatises mention a vocal sound wholly without vibrato as an ornament (Bernhard, Montéclair), which would support the hypothesis that a well-trained Baroque voice normally used minimal vibrato. The same sources mention not only ornamental non-vibrato but also ornamental vibrato. The technique of the latter is described somewhat vaguely, as ‘breath vibrato’. Changes in singing technique later suggest that sound production changed in the latter half of the 19th century; vibrato would thus have had a higher priority before that time.
Measured vibrato, now all but obsolete, was much used throughout the 17th and 18th centuries and in part of the 19th, mostly in orchestral music to underline passages (see below). On string instruments it is rendered by controlled pressure changes of the bow (indicated by a wavy line, and about M.M.60 or 120; a well-known example is found in the scene with the Cold Genius in Purcell’s King Arthur). The choice of quavers or semiquavers serves to suggest the tempo. On wind instruments a measured breath vibrato is indicated with the same device. Singers also use it; here too, the beats should be strictly in time. This kind of vibrato is often said to be an imitation of the Tremulant stop of the organ. Such indications as staccato (or, eventually, such counter-indications as andante) show that repeated quavers or semiquavers in slow movements were generally considered to point to the use of measured vibrato, although the actual performance may sometimes have been less a vibrato than something akin to a portato (as suggested by Roger North); from the mid-18th century on, German writers distinguish between ‘Tremolo’ and ‘Tragen der Töne’.
In ensemble music of the 17th and 18th centuries, measured vibrato is often the only kind accepted, as the specific technique, which relies mostly on carefully gauged fluctuations in intensity, helps the players to stay together and reduces the risk of intonation problems.
Although normal vibrato is also to some extent measured, and most measured vibrato involves fluctuations of pitch, both kinds were mainly connected with only one of their characteristics. As a rule, measured vibrato has strong emotional connotations; its use survives well into the 19th century, most clearly in opera, but also in the symphony. Unlike an ornamental ‘normal’ vibrato, it produces some degree of continuity.
In Western music vibrato has been documented since the Middle Ages. It may have been in use as an ornament even in early Christian music, but here documentary confirmation is lacking. During the 16th century it became fashionable as a mannerist ornament, and towards the end of the century there seems to have been at least one (polyphonic) singing school that would eventually accept it as some sort of a continuous device (described by Zacconi in 1592 as ‘art eventually turned nature’: ‘di natura tale, che usandolo, sempre usar si deve; accioche l’uso si converti in habito’, f.60r). It was then associated with bravura and ornamentational skill (hence the term ardire, sometimes used for bravura vibrato) and was used as the basis of trilling ornaments. This more or less continuous vibrato was rejected by practitioners of solo singing and the new style in Italy, and slowly also elsewhere (in Germany the injunction to sing with a tremulous voice, found in singing tutors for boys, became obsolete during the first half of the 17th century, although some tutors, following tradition, advocated its use until the latter years of the century). As a result of this change of style, vibrato is described as an (occasional) ornament, thus conveying a meaning in accord with Baroque conceptions of passions or with a character as portrayed in a given piece of music. Even in singing tutors of the time it was not mentioned as a substantial element in sound production; there is a clear distinction between the small ‘natural’ vibrato of the well-placed voice, which is considered the same as a non-vibrated instrumental sound, and the audible ornamental vibrato. The association with well-defined passions lacks meaning if vibrato is used continuously as a means of musical tone production (see Seashore). According to 17th- and 18th-century sources, vibrato was associated with fear, cold, death, sleep and mourning, and was generally perceived as a ‘feminine’ ornament (hence denoting also sweetness or loveliness, as reflected in many of the names given to it); its use in this way was eventually superseded by the more modern idea of using vibrato to embellish the tone.
During the Baroque vibrato was used sparingly, for emphasis on long, accentuated notes in pieces with an affect or character to which it was suited. Being regarded as an ornament, in principle it was used on single notes like any other. It was usually denoted by wavy lines; in tablatures a cross (×) has the same meaning. Most of the signs used appear either in tutors or in French amateur music where unspecified ornaments are often indicated by a cross (+). Less common ornaments such as vibrato or glissando were in theory used only by soloists. In the second half of the 18th century there was a tendency towards more vibrato; in some circles it may even have been used continuously.
By the mid-18th century vibrato was gradually identified with some of its more positive connections, especially the sweetness of sound quality (‘lieblich’). With many performers it seems to have been in nearly constant use – at least on all longer notes. Such theorists as Leopold Mozart, Simon Löhlein and Tromlitz warn against overuse. In Classical orchestral works there are many written-out forms of vibrato or similar effects; as a rule these are measured (bow) vibrato, thus allowing small groups to be in time and in tune despite its use. Vibrato at that time also spread among amateur musicians (there is a warning in Bremner); finger vibrato on woodwind instruments as described for amateurs was already known, because relatively little technical knowledge was needed to produce it (English and French sources of the late 17th and early 18th centuries). The early 19th century saw, again, a much more restricted use of the device.
The extensive use of vibrato and measured vibrato in the last decades of the 18th century brought a reaction at the beginning of the 19th; a tendency developed towards a stricter use of prescribed measured vibrato in the symphonic repertory of the first half of the 19th century, and tutors warn against overuse of the normal vibrato, still described as an ornament and not as part of basic sound production. This becomes clear in the fact that during the first three decades of the 19th century wind tutors still describe finger vibrato as the standard technique (e.g. Fürstenau). Nor do singing tutors mention vibrato as a part of normal tone (e.g. Garcia, 1840), and even at the beginning of the 20th century Leopold Auer expressed reservations about the spread of continuous vibrato, which he in no way advocated. In opera abundant use is made of the measured vibrato for dramatic effect until the very end of the 19th century, suggesting that members of Italian opera orchestras were not expected to use left-hand or normal breath vibrato.
In the 20th century absence of vibrato, except for some wind instruments, came to be regarded as a special effect to be employed for character delineation. Only when continuous vibrato began to establish itself did treatises or ‘tutors’ on vibrato in singing and playing begin to appear; there are none devoted solely to the subject until the 20th century. It would seem that the use of metal strings to replace gut strings in the orchestra went hand in hand with an increasing demand for continuous left-hand string vibrato; before this, left-hand vibrato was still reserved for particular effect, as for example in Schreker’s Der ferne Klang (1912). Not until the 20th century was ‘incorrect’ vibrato first seen as a problem; earlier, it had simply been considered as resulting from generally poor technique (especially where singers and wind players were concerned). Continuous vibrato is a 20th-century phenomenon, indicating in itself that the older ornament has lost its expressive power. Regular vibrato has thus become a normal element of sound production, hence an important component of singing and playing technique.
Measured vibrato is as a rule written out by the composer, although use ad libitum may exist. It is used mainly to convey fear and awe, but also supplication and mercy. In late 17th-century German sonatas a tremolo movement is often inserted as a slow movement; this use is also documented by Roger North for the Italian style in general. In his church cantatas, Bach made ample use of measured vibrato, usually with a particular purpose, although there are indications that he and his contemporaries also used it to indicate ensemble vibrato. Especially in small ensembles this use of bow vibrato helps to avoid fluctuations in pitch and speed. Measured vibrato was still used freely by Italian opera composers of the 19th century to denote feminine mourning passions. As a technical exercise it was still taught to string players at the beginning of the 20th century; symphonies of the latter half of the 19th century still have passages with measured vibrato, suggesting that not only in opera orchestras was continuous vibrato (left-hand vibrato for strings) not established before the introduction during the 20th century of metal strings. These paved the way for changes in violin technique and sound perception, one of which was the increasing use of continuous vibrato, not only for solo use. After a period of virtually universal use, playing with little or no vibrato has become increasingly popular through the revival of early music and early singing and playing techniques.
See also Ornaments.
C.E. Seashore, ed.: The Vibrato (Iowa City, IA, 1932)
C.E. Seashore, ed.: Psychology of the Vibrato in Voice and Instrument (Iowa City, IA, 1936)
C. Brown: ‘Bowing Styles, Vibrato and Portamento in Nineteenth-Century Violin Playing’, JRMA, cxiii (1988), 97–128, esp. 110–19
E. Fiebig: ‘Ein tüchtiger Musiker und angesehener Bürger: Johann Christoph Pezel, Stadtpfeifer in Bautzen von 1681 bis 1694’, Das Orchester, xliii/5 (1995), 10–16
F.E. Kirby: ‘The Germanic Symphony of the Nineteenth Century: Genre, Form, Instrumentation, Expression’, JMR, xiv (1995), 193–221
D. Manning: ‘Woodwind Vibrato from the Eighteenth Century to the Present’, Performance Practice Review, viii (1995), 67–72
G. MOENS-HAENEN