The Tuba in the marching band

[Corzhens]

I hope I am not mistaken with the name of this instrument. We call it tuba. It is the biggest brass instrument that is resevered for big guys. Where a thin guy can carry the big drum, but tuba is reserved for muscled men who can carry the instrument as they go along their route. Now my question is the role of the tuba. What exactly is it playing? View attachment 5