[mel-uh-fohn] 
| a marching or military band brass instrument similar in appearance and range to the French horn but slightly smaller and simpler to play. |
[alt-hawrn] | a valved brass musical instrument, varying in shape, that is the alto member of the cornet family. |
| mel·lo·phone (měl'ō-fōn') n. A brass wind instrument, similar to the French horn, often used in military or marching bands. [mello(w) + -phone.] |
mellophone
a valved brass musical instrument built in coiled form and pitched in E or F, with a compass from the second A or B below middle C to the second E or F above. The alto and tenor forms substitute for the French horn in marching bands. In the 1950s a version called the mellophonium was developed for concert use; its French horn-style bell faces forward. The mellophone bears no relationship to the melophone, a free-reed instrument
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əˌfoʊn