The post horn (also posthorn, post-horn, or coach horn) is a valveless cylindrical brass or copper instrument with cupped mouthpiece, used to signal the arrival or departure of a post rider or mail coach. A brass instrument is a Musical instrument whose tone is produced by vibration of the lips as the player blows into a tubular Resonator. Post riders or postriders describes a Horse and rider Postal delivery system that existed at various times and various places throughout history In Great Britain, the mail coach or post coach was a Horse-drawn carriage that carried mail deliveries from 1784 It was used especially by postilions of the 18th and 19th centuries. A postilion (or postillion, occasionally Anglicized to "post-boy" By contrast a Coachman would be mounted on the vehicle along with the passengers
The instrument commonly had a circular or coiled shape with three turns of the tubing, though sometimes it was straight. It is therefore an example of a natural horn. The natural horn is a musical instrument that is the ancestor of the modern-day horn, and is differentiated by its lack of valves The cornet was developed from the post horn by adding valves. The cornet is a Brass instrument very similar to the Trumpet, distinguished by its conical bore, compact shape and mellower tone quality A rotary valve is a type of Valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes [1]
Mozart, Mahler, and others incorporated the instrument into their orchestras for certain pieces. On such occasions, the orchestra's horn player usually plays the instrument. One example of post horn use in modern classical music is the famous off-stage solo in Mahler's Third Symphony. The Symphony No 3 in D minor by Gustav Mahler was written between 1893 and 1896 Due to the scarcity of this instrument, however, music written for it is usually played on a trumpet or flugelhorn. The flugelhorn (also spelled fluegelhorn or flügelhorn) is a Brass instrument resembling a Trumpet but with a wider conical bore
The instrument is still used as the logo of national post services in many countries.