| a straight or coiled copper or brass horn with no valves or slide, originally used to announce mail coaches. |
post horn
brass musical instrument of cylindrical bore, used by guards of mail coaches in the 18th and early 19th centuries. At the end of the 18th century, post horns were crescent-shaped, coiled, or straight. The notes they sounded were at most six (harmonics 2 to 7). The post horn gave rise to the cornet in the 19th century, when valves were applied to it.
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