mellophone

noun

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

   “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.”

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

   “[…] 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.”