Antonio de Torres was perhaps the most important figure in the history of the development of the classical guitar. While many of the design features of Torres’ guitars can be found in instruments built by earlier makers, Torres integration of these features with his own design concepts established a standard for the instrument that has stood the test of time.
José Romanillos has provided an invaluable resource for those interested in Torres’ guitars with his book Antonio de Torres, Guitar Maker – His Life and Work. Romanillos’ book on Torres catalogues 88 instruments built by Torres between 1854 and 1892. Torres’ work is divided into two periods, or epochs, when he was active building guitars. This includes 39 instruments from the first epoch from 1854 through 1868 and 49 instruments from the second epoch from 1875 through 1892.
With the dimensional data provided in Romanillos’ catalogue, it is possible to investigate some of Torres’ design principles in ways not possible before. Most of the analysis in the articles contained here is based on this data. The objective has been to better understand Torres’ approach to guitar design and construction and how his approach evolved over time.
Romanillos assigned a catalogue number to each Torres instrument to designate its construction sequence. Guitars from the first epoch are given the designation “FE” followed by a construction sequence number. First epoch instruments were not numbered by Torres so Romanillos has assigned them sequence numbers. Guitars from the second epoch are given the designation “SE” followed by a construction sequence number. In some cases, the catalogue number has been augmented with a letter (A, B, C, etc.) where a new instrument has come to light since the original catalogue. The letter “U” has been used to designate an instrument where the sequence number on the label (typically added by Torres for second epoch labels) is missing our illegible.
Care should be taken when attempting to infer design principles using data from historical instruments. The hand construction techniques used could have introduced variability in finished dimensions. Damage and repairs over time may have altered original dimensions. The curved and rounded surfaces of a guitar present measurement challenges and expansion and contraction with temperature and moisture, as well as measurement accuracy and precision, can lead to different measured dimensions for the same guitar. As an example of this last point, comparing the differences in dimensions from different sources for three Torres guitars, I have found differences of up to 5 mm for the same dimension for the same guitar between two sources. It should also be noted that data from additional Torres instruments might alter the results of the analysis described in these articles. Romanillos estimates that his catalogue only represents a fifth of Torres total production
Romanillos provides dimensional data for scale length, body plan dimensions (including body length and upper bout, lower bout and waist width), soundhole diameter, and side depth at the top, waist and bottom of the instrument. The data is incomplete for some instruments. The analysis which follows is based primarily on the dimensional data provided by Romanillos in his catalogue. All dimensions are in millimeters.
In the graphs that follow, dimensional data is analyzed for frequency, construction sequence, and correlation between dimensions. In figures depicting the correlation between dimensions, the correlation coefficient R2 is used. This coefficient is calculated using linear regression to determine a line of best fit to the data. R2 is a measure of how well the line approximates the actual data. An R2 of 1.0 indicates that the line fits the data perfectly. For example, an R2 of 0.7 means that 70% of the variation may be explained by the variables shown with the remaining 30% percent explained by other factors. Note that while high correlation may provide insight regarding relationships between the variables, it does not prove causation.
Modern Practice:
How important was Torres in establishing a standard of guitar design and how much have design concepts changed since his time? Sheldon Urlik’s catalogue of his guitar collection can be used as a point of reference for guitars built after Torres. It includes 82 instruments built between 1867 and 2009 by more than 60 makers. Of those, 63 are classical guitars (vs. flamenco) of which 4 are by Torres.
Urlik has just published a second edition of his book and the analysis based on Romanillos’ catalogue is being supplemented where possible by the data from Urlik’s catalogue. Articles will be supplemented from time to time as this analysis is completed.
Sources:
José L. Romanillos, Antonio de Torres, Guitar Maker – His Life and Work, (Westport, CT, USA: The Bold Strummer, Ltd., 1990)
Sheldon Urlik, A Collection of Fine Spanish Guitars from Torres to the Present, Second Edition (Commerce, CA, USA: Sunny Knoll Publishing Company, 2015)
John Saucier, Design Analysis of Torres Guitars Based on the Catalog of Romanillos, American Lutherie, Number 113, Guild of American Luthiers