Joseph Haydn, 1732-1809
Trio in C major, Hob. XV: No. 27, circa 1794, published 1797
Haydn is well known for his monumental achievements with the symphony and the string quartet; he produced a combined total of works in both genres numbering around one hundred and forty-two. But Haydn was prodigious in at least two other genres at the heart of the classical tradition: the keyboard sonata and the keyboard trio, both transitioning from the harpsichord to the piano during the course of his career. Haydn composed something like fifty keyboard sonatas and another forty or so keyboard trios of which over thirty have been authenticated. The final ten "late" trios were written between 1794 and 1797 specifically for the piano rather than the harpsichord. They are known as the "London Trios" since Haydn wrote them primarily during his second, marvelously successful trip to England following his retirement from service to the Hungarian Esterházys. Every one of the final trios is considered a masterpiece and a founding example in yet another nascent genre in which Haydn exercised his supreme gift for sonata forms.
The string quartet emerged by absorbing and thereby disposing of the Baroque era accompaniment known generally as continuo, a role most commonly fulfilled by a keyboard (often with additional bass instruments). Where before, the keyboard player would largely improvise a part to supply the full harmonies for the ensemble, now, the necessary harmonies were incorporated into the fully composed parts for strings, an accomplishment that renowned British musicologist Donald Tovey called "utterly miraculous"—a feat which can almost be attributed to Haydn single-handedly. Curiously, the piano trio emerged by a different process which was additive rather than reductive: for color, variety and an opportunity for the dilettante to participate, composers added simplified, optional parts to the otherwise solo keyboard sonatas creating a new genre called the accompanied sonata. Starting with French composers such as Mondonville and Rameau, the accompanied sonata provided a lucrative market for such proto-classical composers as Schobert and the Bach sons. Schobert and C. P. E. Bach significantly influenced Haydn and Mozart. In many of these sonatas, the additional parts for flute, violin or cello were optional ("ad libitum"), unnecessary for the integrity of piece. The accompaniment was often merely a doubling of the treble and bass lines in the keyboard part, but these additional parts added valuable flexibility in a market for domestic music making. With Haydn, the artistry of his conceptions made these parts essential to the character of the music, especially the violin part. Haydn's trios represent the ultimate artful realization of the accompanied sonata before its historical demise, leaving the evolution of the modern piano trio for three equal players to Mozart.
Haydn's Trio in C Major was published in 1797, one in a set of three dedicated to Theresa Bartolozzi (née Jansen), a London friend and an accomplished pianist. Scholars believe that it was likely composed around 1794, seven years after Mozart's final piano trio and around the same time that Beethoven was finishing his own first such works. Within a genre associated, at the time, with the musical amateur, this celebrated trio features a demanding piano part, particularly in the outer movements. Typical of most piano trios before Beethoven, it features three (rather than four) movements in a fast-slow-fast arrangement, in this case, two sonatas flanking an inner movement with a simpler three-part form. The opening allegro is a crisp sonata with a supple exposition marked by its opening fanfare, delicious pauses, lyrical grace and sparkling piano runs for music that captivates through charm. So much more than merely gallant, the development intensifies into a headlong momentum with a texture and drive that is practically Baroque, an ideal foil for the highly articulated eloquence of the classical recapitulation. Throughout, the poor "dilettante" violinist is tasked with fleet embellishments, occasional leads, double and triple stops (chords involving multiple strings). The second movement follows a clear ABA ternary form: it begins with a sweet andante in A major that suddenly pounces with heavy accents into the severity of A minor, a dramatic departure Haydn coaxes back through radiant transformation. The cello proves indispensable for the intensification of mood. The finale is a Haydn specialty, a hybrid of sonata and rondo form with the harmonic motion and development from the former and the recurring refrain from the latter. A swift and jolly presto that develops into sections of fierce drive (as in the opening movement), it features fast-paced conversational exchanges between piano and violin. Here, the violin is prominent and essential in a way that challenges the trio's historical origins as "accompanied" sonata.