It's used extensively by bandsmen (8)
I believe the answer is:
trombone
If this is the answer I cannot explain how the clue works.
Can you help me to learn more?
(Other definitions for trombone that I've seen before include "Bfrass wind instrument with slide" , "Brass musical instrument with slide" , "Brass band instrument" , "Musical instrument with long slide" , "play this" .)