Virginal

Este artigo dá uma visão dos tipos de instrumentos de teclado que se desenvolveram desde a Antiguidade até o período Barroco, dando início a uma série de artigos a serem publicados na "Revista Teclas e Afins" (Brasil), no intuito de revisitar cada um destes instrumentos, com base em importantes publicações na área acadêmica.

This article gives an overview for types of keyboard instruments developed since the antiquity to the Baroque era, starting a series of articles to be published on "Revista Teclas e Afins" (Brazil), in order to revisit each one of these instruments with basis on important academic area publications.

At the Edinburgh University Collection of Historical Instruments (EUCHMI) there are two virginals where the strings are plucked extremely close to 1/4 of their length over a substantial part of the compass. Principles of Acoustics dictate that in such cases the fourth partial of the resulting sound is unlikely to be produced with any appreciable magnitude. Similar situations affecting different partials also occur when the plucking point is located at other fractional parts of the string length, such as 1/3 or 1/5. A database of plucking points, based on museum catalogues, was created and analysed, so that pitch regions are identified where such phenomena are likely to occur for different categories of instruments.
The main cue used in harpsichord tuning is related to beat phenomena produced by partials of two simultaneously played notes, whenever there is a small difference between their frequencies. Partial four being relevant for major thirds and perfect fourths, these intervals may result less accurate, or less reliably tuned, in instruments like the above virginals.
Historical sources were surveyed for expressions which describe the cues that tuners were supposed to use in identifying the ideal of an interval. Although expressions such as Schwebungen are mostly related with beats, broader meanings are discussed. Hints of the use of alternative, not beat-related cues, are identified.
A series of practical tuning experiments was performed in which selected intervals were tuned, the accuracy of the tuning process being assessed from recordings, which were subjected to spectral analysis. Only cues that could be related to historical sources were used. The effects of factors such as pitch, pitch region, instrument, interval type, and particularly the potential absence of relevant partials were investigated, statistical methods playing a substantial role in the research.
A logbook was created, where the experimenter detailed the cues used for each tuned interval in one of the experiments. The recorded information provided some insight into a number of strategies a tuner may use for coping with difficulties in cases of absent or weak partials.
The impact of inharmonicity on the exact size of just intervals was also examined, both on theoretical grounds and based on data from the experiments.
A number of case studies were included, where a comparison was made between missing partial notes predicted from plucking points and the degree of absence of those partials in the actual spectra for some historical instruments.""

The Russel Collection of Early Keyboard Instruments includes two virginals, one polygonal made in 1586 by Alessandro Bertolotti, another rectangular made c.1620 and attributed to Francesco Poggio. Although their construction is quite different, they share a remarkable similarity in one aspect: from C to e'', and with only two exceptions, their plucking point percentages match to within 1%.
Plucking a string nearer or farther from its end is a well-known way of obtaining different timbral qualities from a harpsichord, so it might be expected that these two virginals would sound very much alike. However, this is not the case, as the timbral difference between these instruments is easy to spot.
In this paper, the Bertolotti and Poggio virginals are compared from the point of view of both sound and construction. As a case study, they allow us to access:
a) how relevant to its timbre is the plucking point profile of an instrument?
b) which other constructional details might be important to the timbre of a virginal?
Despite their differences, the sounds of these instruments do have some degree of similarity, both from the physical and sensorial point of view. This similarity is highlighted by contrast, through comparison with two other virginals, by Honofrio Guarracino (1678) and Stephen Keene (1668), with different plucking point profiles. Illustration is provided through recordings of a short musical passage played in each instrument.

"Ich ging einmal spazieren" est le titre d’une mélodie populaire à l’origine des 31 variations du compositeur allemand Hans Leo Hassler (1564-1612), l’une des œuvres pour clavier les plus impressionnantes de la fin de la Renaissance. D’une durée totale de plus de quarante minutes, l’œuvre est sans équivalant dans le répertoire pour clavier de cette époque – à l’exception peut-être des 30 variations de John Bull (1562/3-1628) sur Walsingham. Seules les Variations Goldberg, un siècle et demi plus tard, dépasseront cette durée. Les variations de Hassler sont donc tout indiquées pour marquer la reprise des concerts de musique ancienne après la pause estivale et la fin de l’intégrale Johann Sebastian Bach, donnée de 2013 à 2015 à l’espace dAM.

La virginale d'Henri Van Casteel, construite à Bruxelles en 1770 alors que le facteur rentre de Lisbonne, mêle des éléments de la facture du nord de l'Europe à des caractéristiques observées sur les clavecins et pianoforte portugais conservés. Elle témoigne vraisemblablement des us et coutumes de la facture ibérique des virginales ou clavicordios. Dans la mesure où celle-ci n'était jusqu'à présent documentée que par des sources écrites, la virginale de Van Casteel constitue donc un témoignage particulièrement précieux.