Assertion: tuba | /r/HasProperty | instrument
Facets:
Source sentences:
text: Most marching bands opt for the sousaphone, an instrument that is easier to carry since it was invented specifically for this and almost always cheaper than a true marching tuba.  
text: A Tuba is one of those instruments where you don't notice the sound to much when its in a piece of music, but whenever it's not there something definitely sounds missing and weird.