What is a bell brace on trombone?

A bell brace is a metal rod or bracket that connects the bell of a trombone to the slide. It helps to keep the trombone in shape and to prevent the bell from vibrating excessively. Bell braces are typically made of brass or nickel silver, and they can be either fixed or adjustable. Fixed braces are permanently attached to the trombone, while adjustable braces can be moved up or down to change the tension on the bell.

Bell braces are an important part of the trombone's design. They help to ensure that the trombone sounds its best and that it is easy to play.