Stewart Pollens
 

Fine Musical Instrument Expert and restorer

Few violinists stop to consider how an instrument designed in the sixteenth century can be so successfully employed in the performance of music of the Romantic and post-Romantic eras. The answer is primarily in the fittings. By installing angled, reshaped, and mortised necks, longer and stronger bass bars, tighter sound posts, and taller bridges, restorers transformed violins made in the Renaissance and Baroque periods to sonorous powerhouses suitable for playing Tchaikovsky, Brahms, and Stravinsky.

The bass bar provides structural reinforcement and affects acoustical quality by simultaneously impeding and transmitting vibrations from the bridge’s bass foot throughout the violin’s top.  As far as we know, the violin (which evolved from the vielle, rebec, and lira da braccia in the early sixteenth century) has always had a bass bar. Those mounted in fine violins are generally fashioned out of choice pieces of spruce that have been carefully trimmed and glued in place beneath the bass foot of the bridge and inclined slightly with respect to the centerline of the instrument. This system appears to have been employed in the earliest known Cremonese violins made by the Amati family. The Hills were of the opinion that some of the early Brescian makers, such as Maggini, glued in their bass bars as well, though they were less certain that Gasparo da Salo did so in all of his instruments.¹  Some early violins and viols, folk fiddles, and cheap commercial violins have bass bars carved out of the top plate (some along the center line rather than under the bass foot of the bridge), and a few historians have theorized that the earliest violins may have been made in this way.²

Stewart Pollens fitting a violin bass bar

The bass bars of most sixteenth- through eighteenth-century violins have been replaced, and this can be said for a great many nineteenth-century violins as well. Bass bars support the longitudinal arching of the violin’s top, and if the arching has collapsed from the pressure exerted by the strings and bridge feet, one method of restoring the proper curve is to put in a new bar. When heavier overspun strings began to be used at the end of the seventeenth century, violins came under greater tension, and longer and stouter bass bars gradually replaced the more delicate original ones to help the instruments cope with the added stress. Rising pitch also caused string tension to increase, and this was another factor responsible for the installation of stronger bass bars.
  
The acoustical function of the bass bar is not well understood, and surprisingly little scientific work has been done to discover precisely what it does and how it may be proportioned and installed to make it work better. Empirically, violin repairmen have found that new and heavier bass bars tend to restore or increase sound projection. In fitting a bar, some restorers trim it so that it fits perfectly prior to gluing, while others maintain that some structural or acoustical advantage is gained by giving the bar an extra bit of curvature and gluing it in under tension.  Scientific studies of violin plate vibration have shown that the bass bar has a stiffening effect upon the top, which raises its modal frequencies.³  One very interesting study by Thomas Croen and William Atwood has demonstrated that the bass bar compensates for the loss of longitudinal stiffness that occurs when the f-holes are cut, and that bass bars installed under tension cause the violin’s high-frequency response to increase significantly.⁴  

We tend to think of the work of Stradivari as the pinnacle of violin making, yet Count Cozio di Salabue (the famed late-eighteenth and early-nineteenth-century collector) sent new instruments that he had bought in 1774 from the merchant son of Antonio Stradivari directly to the Mantegazza brothers in Milan to have them “thinned to perfection” and renecked to suit the prevailing tonal aesthetic. Cozio remarked that three of the instruments he had acquired from Paolo Stradivari had bass bars that were not properly glued in.  He also wrote that some of these instruments had already been thinned to an extreme in order to produce a nasal sound that previously had been fashionable.⁵  Twenty years after Cozio’s death, many of the instruments from his collection were again “modernized” in the shops of Paris luthiers, and by the end of the nineteenth century they were once more renecked and rebarred in London. When such instruments found their way to New York in the twentieth century, the procedure was repeated. As a consequence, few original or early bass bars have survived.

The Hill bass bar collection includes fifty bass bars: thirty-nine for violin, seven for viola, and four for cello. These were carefully removed by the Hill workmen (including Alfred Ebsworth Hill, who initialed some of them) in the course of restoration and marked with the maker’s name and the date. In some cases, there are supplemental remarks (see Table 1). Data on nineteen bass bars are tabulated in the Hills’ Antonio Stradivari: His Life and Work, and though most of these can be identified among the fifty bars that form the present collection, there are some notable exceptions.⁶  For example, the bass bar dated 1716 is undoubtedly the one that is presently displayed in the Ashmolean Museum, Oxford, with the violin known as the “Messiah” (note that it is somewhat longer than the original Stradivari bars documented in this article). The Hill bass bar collection was listed by Sotheby’s, London, in their October 1995 sale of musical instruments, though it was not sold, and Mr. James Warren of Chicago purchased it privately from the Hill family.⁷

In 1969, Robert Lewin reported that the violin maker Cyril Jacklin possessed notebooks, patterns, and other relics once owned by Joseph Maurice Somny, the Mirecourt-born violin maker and restorer who worked for the Hills at both their Hanwell and Baker Street, London, locations between 1888 and 1931. Among these relics were a number of bass bars, which were presumably removed by Somny when he was employed by the Hills. It is not known whether these were ultimately recovered by the Hills and whether they are now part of the collection presented here.⁸

Gross dimensions, weight, and grain direction for each bass bar are given in Table 2. Modern makers generally employ vertical-grain (radially cut) spruce for their bars. Curiously, many of the bars in the Hill collection are sawn on the slab (tangentially cut), including one of the five that came out of Stradivari’s instruments. Slab-sawn spruce has a lower Young’s Modulus (a measure of stiffness) than vertical-grained spruce (approx. 1.03 vs. 1.56). This means that a bass bar cut on the slab is somewhat more flexible than one that is vertically grained and comparably dimensioned. To provide the same stiffness as a vertically grained bar, a slab-cut bar would have to be made stouter and thus heavier.⁹ The grain of many of the bars in the Hill collection is not precisely oriented in either the radial or tangential direction, and it should be noted that the Young’s Modulus for a beam of wood that has angled grain (chordally cut) is lower than that of slab-sawn wood.¹⁰

The Hills presumably felt that these bass bars were original. However, in cases where several bass bars are associated with a particular maker, there are often stylistic differences between the bars. For example, of the two bars marked A. & H. Amati, the longer one is slab-sawn and gradually tapers to points at either end, whereas the shorter bar has vertical grain, is squared off at the ends, and is fairly uniform in width throughout. Of the bars marked Nicolo Amati, the one that is dated 1665 has a delicately curved profile, whereas the 1671 bar is more crudely fashioned. Regarding the Stradivari bars, the bar marked 1703 has vertical grain, whereas the bar from the 1704 “Betts” is slab-sawn. Both come to points formed by two straight, intersecting knife cuts, whereas the ca. 1680 and 1719 Strad bars have squared-off ends. (The tip of one end of the “Betts” bass bar was broken off and a new piece was scarfed on by the Hills.) Of the G. B. Guadagnini bars, one has vertical grain, while the other is slab-cut. The Stainer violin bass bar has the tight, wiggly grain pattern that one often observes in the tops of Stainer’s instruments, which supports its authenticity.

Because these bass bars have been separated from their instruments, it is difficult to draw precise conclusions about the acoustical qualities they once imparted. Their general delicacy, however, speaks of another time and reminds us that the sound made today by Strads, Guarneris, Amatis, and others is quite different from that produced by these instruments when they left their makers’ hands. It is hoped that this documentation will be of use to those building and restoring violins for early music ensembles and soloists.

I would like to thank the present owner of the collection, Mr. James Warren, for generously allowing me to examine and to write about them.  Photocopies made from full-size photographs of the violin and viola bass bars may be obtained by contacting the author.                                                                       

Viola Bass Bars

40. Rocca. 1834. / Guarnerius. Copy.
41. Taken from Jacobus Stainer 1660
42. M. Albani, 1688. Tenor.
43. J. B. Guadagnini Tenor. 1757.
44. Ferdinandus Gagliano. 1783.
45. V. Panormo / Taken from Panormo tenor 10/4/59
46. V. Panormo. 1800. (Alto)
 

Cello Bass Bars

47. Antonio Catini. Modena 1660. or 8.
48. Antonius. Stradivarius. 1667. Taken out in 1893. A. E. H. / Strad:V:Cello:purchased in Sicily. 1893.
49. A. Gagliano, 1725
50. Januarius Gagliano, 1736

*Inscriptions and punctuation follow the original

 Table 2

Measurements of Bass Bars**