The keyed trumpet-the fruit of the evolutionary process

The trumpet, which stands out for its flamboyance even among other brass instruments, is a truly elegant instrument that can just as easily charm the listener with sweet cantabile as it can deliver a heroic fanfare.
Until the mid-nineteenth century, however, the trumpet did not incorporate any devices like valves or pistons, and the only technique that the trumpeter could rely on was lip control. As a result, the instrument was also limited in terms of the notes that it could produce. It could not reproduce elegant phrases replete with semitones, but could only play simple notes such as C, E, and G.
There will always be people who will try and overcome such limitations, however. Anton Weidinger-an outstanding Viennese trumpeter of the Classical period-was one such man. By adding keys to the tube, he devised an instrument that could play semitones. Weidinger requested a number of composers to write concertos for this new trumpet. Two that complied with his wishes were Joseph Haydn and Johann Hummel. Although Weidinger's keyed trumpet was rendered obsolete by the appearance of the more functional valve trumpet in the mid-nineteenth century, it was due to his unquenchable spirit of enterprise that the two greatest trumpet concertos in classical music came to be written.