The Cornet
The cornet is very similar to the trumpet, distinguished by its conical bore, and mellower tone quality. The cornet was invented by adding valves to the French post horn in 1814. The valves allowed for melodic playing throughout the register of the cornet. Trumpets were slower to adopt the new valve technology, so for the next 100 years or more, composers often wrote separate parts for trumpet and cornet. The trumpet would play fanfare-like passages, while the cornet played more melodic passages. The modern trumpet has valves that allow it to play the same notes and fingerings as the cornet.
Modern Cornet Ancient Post Horn