mellophone

plural mellophones

1. A brass instrument frequently used in place of the French horn in marching bands and similar performance groups.

   A pupil wishing to study the French horn will make more rapid progress by having at least a year's experience on the mellophone.

   1920, Glenn Howard Woods, “Introduction in the Elementary Schools” (chapter V), in Public School Orchestras and Bands, Oliver Ditson and Company, page 46

   2 more examples

   On the issue of the mellophone being used as an introductory instrument for a beginning French horn student you must consider the fact that although they look similar, the instruments are entirely different.

   2016, Michael J. Pagliaro, “How Brass Instruments Compare to Each Other” (chapter 9), in The Brass Instrument Owner's Handbook, Rowman & Littlefield, →ISBN, page 158

   […] yet for concert work I much prefer the mellophone (where French horns are not available) played in a creditable manner to the upright alto as played by some of the alto players I have heard who pose musicians.

   1916, “Letters”, in The Musical Messenger, volume XII, number 2, page 23