Sideways view of the tuba.
Marching tubas are called sousaphones. They are named after their inventor, John Philip Sousa, who was a famous composer and bandmaster. It wraps all the way around the player's body and has a large bell that rises up over the player's head. The sousaphone is pitched in E-flat and double B-flat. It plays an octave lower than the trombone and two octaves lower than the trumpet.
Concert tubas, played indoors, are balanced on the edge of the player's chair or on the player's lap. The bell of a concert tuba usually points straight up at the ceiling
The longest and lowest tuba is the double B-flat tuba, which is the same length as the sousaphone. There are also tuba that have a pitch in double C, F, and E-flat.
A tuba has at least twelve feet of tubing.
Information found at http://www.sbgmusic.com/html/teacher/reference/instruments/brass.html
