A brass wind instrument is a type of musical instrument that produces sound by blowing air through a tube. The two most common types of brass wind instruments are the TUBA and the SOUSAPHONE. The TUBA is a four-letter word and is the largest and lowest-pitched instrument in the brass family. It is usually used to provide a bass line in orchestras and concert bands. The SOUSAPHONE is a ten-letter word and is a type of TUBA designed to be easier to carry and play while marching. It is often used in marching bands and military bands.