Joseph Haydn wrote as many as 123 trios for the unusual combination of baryton, viola and cello, and three further trios for baryton, cello and violin (Hob. XI:89-91) are considered part of the series.^[1] As Sisman notes, they are the “most intensively cultivated genre” of Haydn’s early career.^[2]

The baryton is a bowed string instrument of the viol family played in Europe during the 17th and 18th centuries. It has six or seven strings of gut, arranged over a fretted fingerboard, plus a lower set of wire strings. When the gut strings are bowed, the wire strings vibrate sympathetically, enriching the tone. The wire strings may also be plucked by the performer's left thumb, creating a contrasting tonal quality. For full information, see baryton.

Haydn began composing baryton trios in 1765. At the time he had been working for the princes of the Esterházy family since 1761, and since 1762 for the newly reigning Prince Nikolaus. Nikolaus had previously played the viola da gamba (an instrument similar to the baryton, but without the sympathetic strings), but in 1765 he purchased a baryton.^[3] In the same year, Haydn received an official reprimand from the prince for neglecting his duties; for details of this episode see Gregor Werner. An addendum to the reprimand specified that Haydn should also spend more time composing works for the Prince's new instrument:

"Finally, said Capelmeister Haydn is urgently enjoined to apply himself to compositions more diligently than heretofore, and especially to write such pieces as can be played on the gamba [i.e., baryton], of which pieces we have seen very few up to now; and to be able to judge his diligence, he shall at times send us the first copy, cleanly and carefully written, of each and every composition."^[4]

Haydn responded vigorously to this command, and his efforts soon met with the Prince's approval. On 4 January 1766, Esterházy wrote to his administrator:

"I have this moment received from Hayden [sic] three pieces which please me very much. You are accordingly to pay him in my name twelve ducats from the treasury and to tell him at the same time that he is to write six more pieces like those he has just sent me, together with two solos, to be delivered as soon as possible."^[5]

These gratuities were to continue.^[6]

Over the next ten years Haydn wrote "nearly 200"^[7] compositions for various ensembles with baryton. Of these, the predominant genre was the baryton trio. Whenever Haydn had completed 24 trios, he had the set "richly bound in leather and gold" (Sisman). The resulting volumes were dated 1766, 1767, 1768, 1771, and 1778;^[8] the last was bound up after the prince had abandoned the instrument in favor of a new hobby also involving Haydn, namely the mounting of opera productions in his palace. According to barytonist John Hsu, the last trios actually date from 1775.^[9]

The Prince's instrument was built in 1750 by Johann Joseph Stadlmann of Vienna,^[28] a famed violin maker who later did business regularly with the Esterházy musical establishment.^[29] This baryton had seven bowed strings, tuned like a bass viola da gamba (to which the sound of the bowed baryton strings is comparable); i.e. A', D, G, c, e, a, d'. There were ten wire strings, tuned in a D-major scale, plus the A a fourth below and the E a major second above.^[30] (Since Haydn's baryton works dominate modern performance on the baryton,^[31] it is this form of the instrument that is most often constructed today.) The instrument has been described as follows: it "is made of pine and maple and lacquered in light yellow. The sides and the back are decorated with undulating lines of inlay; on its extra fingerboard there is a foliated scroll inlay of bone and wood. The peg-box ends in a carved, painted moustachiod head wearing a shako. The original case is covered with leather studding with gilded nails."^[32]

John Hsu estimated that the Prince was probably not a virtuoso on his instrument, judging from the difficulty of Haydn's writing. The composer used only the top five of the seven bowed strings, and seldom required the player to pluck and bow simultaneously. The keys chosen are also the simplest to play in: D major and the neighboring keys of G major and A major.^[33]

According to Pamplin, the tuning of the wire strings on the Prince's baryton was a special one, not typical of the baryton tradition as a whole but reflecting the particular needs of the music written by Haydn (and various of his colleagues) for Prince Esterházy. In most barytons, the wire strings were often tuned in the range of the three lowest bowed strings. As such, they were used to provide a bass line underneath a bowed melody in solo playing. Haydn seldom wrote such music (which is quite demanding for the player), thus respecting the needs of his amateur patron. The wire strings of the Prince's instrument were instead tuned in the same range as the highest three bowed strings. Through sympathetic vibration, they enhanced the timbre of the melody line, thus serving the baryton's role as the primary melody instrument in this music.^[34]

Prince Esterházy's instrument was kept in the family's collections after his death. Much later (1949), it became the property of the (then-communist) Hungarian government when, on coming to power, it confiscated the Esterházy estates and installed the instrument in the Hungarian National Museum in Budapest, where it may be viewed today.^[35]

A relatively negative assessment of the baryton trios is offered by David Wyn Jones, who writes that they "could be written on automatic pilot (though one prone to creative computer error)."^[36] Referring to Prince Esterházy's command to compose the music (from the 1765 reprimand document described above), Jones comments, "Very few people played the [baryton] and this command from the prince must rank as one of the most indulgently self-interested in the history of musical patronage."^[37] Other Haydn scholars tend to be more positive; while generally acknowledging the limited scale and aspirations of the trios, they express admiration for Haydn's craft in composing them. Thus, James Webster: "the baryton trios ... are finely wrought compositions, as rewarding in their way as the raw expressionism of the Sturm und Drang";^[38] Karl Geiringer: "A number of fine specimens are to be found in this collection, showing that Haydn gave of his best even when he did not expect his compositions to be heard outside the court of his prince";^[39] Lucy Robinson: "Despite the limitations of the combination, Haydn's genius is evident in the kaleidoscopic range of melodic and textural ideas and the witty interplay between instruments."^[40]

John Hsu wrote (1986), "Throughout the trios, there is a feeling of intimacy. This is the most private of chamber music, written especially in response to the wishes and needs of one person. We can easily imagine the satisfaction and inspiration which Prince Esterházy experienced while playing these trios."