July 3, 2012 5:40:43 PM EDT
I played with one for several years and they do not look like a trumpet mute. They look like a donut. Some people actually call them that. What happens when the mute is inserted into the bell is it makes the low notes less harsh and helps them blend into the rest of the register and takes some of the overtones out in the higher range so its not as bright. Another great aspect of the mute is it brings the low B and Bb in tune. It's almost like covering your bell with your hand and it plays a low A except it doesn't get that covered with the mute just enough to bring the pitch in tune. You can buy them at a store or make one yourself.