sousaphone

noun1

1. •
   A valved brass instrument with the same length as a tuba, but shaped differently so that the bell is above the head, that the valves are situated directly in front of the musical instruments and a few inches above the waist, and that most of the weight rests on one shoulder.

   • One version of the large tuba, popular in marching bands, is called a sousaphone in honor of bandsman John Philip Sousa. — 1990