Antonio Soler and Keyboard Sonatas

Antonio Soler (1729–1783), one of the most exceptional musical figures of the late Baroque and early Classical periods in Spain, was highly productive and left behind a substantial body of work, including almost 200 keyboard sonatas, six quintets for string quartet and organ, and a unique set of concertos for two organs—this is just a partial list of his creations. He also wrote a treatise on harmony, Llave de la Modulación (Key to Modulation), and unexpectedly authored a treatise on currency exchange rates.

Also known as Padre Antonio Soler, he was a Hieronymite monk and a priest. Soler served as the mestre de capella (Chapel Master) at El Escorial (the Escorial Royal Palace in Madrid), where his varied responsibilities included teaching, performing on the organ, and composing for all the church services. Considering the role Soler played, his music reflects a different personality—full of wit, flamboyance, and playfulness. Through playing his keyboard sonatas, Soler’s personality vividly reveals itself to me—I imagine he must have had an agile mind brimming with ideas, always seeking unusual paths to explore instruments and compositional materials, with the confidence to master different instruments.

His keyboard sonatas are probably his best-known and most recorded and performed works, but they remained unknown until the 20th century, when they were rediscovered by two pianists and scholars, Samuel Rubio and Frederick Marvin. The sonatas are assigned numbers with "R." and "M." There are assumptions that Soler was a student of Scarlatti, and his keyboard sonatas are often compared to Scarlatti’s due to their similar form and highly challenging keyboard techniques. For example, both composers favored wide jumps, hand crossings, and thirds in scales.

Perhaps due to his interest in music theory and harmony, as seen in his treatise on harmony, Soler’s works often surprise listeners by modulating to rare keys and revealing completely different keys in the second half of the sonata. For example, in his keyboard Sonata R.88, the original key is D-flat major, but he begins the second half in F major, breaking the traditional rule of binary-form sonatas, which typically start the second half in the dominant, subdominant, or relative major/minor key (see marked score Fig. 4 and 5). Moreover, Soler expanded on the   virtuosic keyboard techniques of his mentor, Scarlatti. Both composers frequently used hand-crossing techniques in their sonatas, such as in Scarlatti's Keyboard Sonata K. 113 and Soler’s Sonata R.10 (see Fig. 6 and 7). While Scarlatti used a range spanning a compound tenth within  three octaves, Soler extended some of these intervals to more than three octaves. In the same sonata by Soler (R.10) (see Fig. 8), he also added elements like wide leaps and extended trills to  create a flashy yet lively effect. All these examples reflect his artistic character and personality—without a spirit of exploration and experimentation, he would not have been able to create music that is both technically demanding and musically captivating.