Times change and musical instruments change with them. The trumpet, for instance, had originally been able to play only notes of the natural overtone series. In the Baroque era, a special technique existed to make the most of this situation. The overtones are closer together in the second octave than they are in the first; in fact, after the seventh overtone, they more or less add up to a complete scale. The special technique consisted in developing the player’s skills at playing in the high register (known as the “clarino”) register. Yet in the Classical period this was no longer sufficient; in fact, the need arose to fill out the gaps in the instrument’s lower range and to provide it with a full chromatic scale in all registers.

Several methods were devised to accomplish this, but none was entirely satisfactory until the first valve trumpets were constructed in the early 19th century. A transitional stage in the instrument’s evolution was represented by the keyed trumpet championed by the Austrian virtuoso Anton Weidinger (1767-1852). About Weidinger’s instrument, known as the organisirte Trompete, specialist Reine Dahlqvist has written: “The keys are brought together on one side of the instrument so as to be operated by one hand only; the other hand merely holds the instrument… The keys cover soundholes, and when opened raised the pitch: the key nearest the bell a semitone, the next by a tone, etc.”

Weidinger had been a member of the court opera in Vienna since 1792. He probably met Haydn when the latter returned from his second trip to London. Haydn agreed to write a concerto for this instrument, and produced a work that stands as a splendid example of his late style. Trumpet players are certainly not oversupplied with concertos by major composers; it is therefore all the more curious that Haydn’s trumpet concerto remained virtually unknown until the 20th century. It wasn’t published until 1931, and it was only in the 1950s that it began to attain the popularity it deserved.

Classical concertos usually start with an orchestral exposition during which the soloist is silent. In this case, however, the soloist plays a single loud note and two short fanfare motifs during the tutti section. This was probably to allow the soloist to warm up in preparation for the solo. The solo exposition gave Weidinger the opportunity to demonstrate what his new-fangled instrument could do. But Haydn was evidently concerned with more than demonstrating: he used the chromatic notes of the keyed trumpet to shape melodies of great sensitivity that alternate with more typical, fanfare-like trumpet writing. The second-movement Andante has a gentle lyrical tune that the solo trumpet takes over from the violins and the first flute; it has to match these traditional “singing” instruments in gentleness and expressivity. The chromatic notes of the trumpet, as well as its ability to play fast-moving ornaments, are put to good use in this brief but memorable movement. The last movement is a typical Haydnesque contredanse finale, with themes reminiscent of a popular dance type of the period woven into a brilliant rondo that displays the virtuosity of the soloist along with (one more time) his sensational chromatic notes.