Mutes are usually made from materials like rubber, wood or metal and are helpful when you want want to practice at a quieter volume or when a piece of music has a the marking 'con sordina' which means 'with mute'.

They attach to the bridge of your instrument and dampen the sound. Two of the more popular styles of mute are the tourte mute and the practice mute. A tourte mute is typically round and is placed on a single string. It is best used for classical musicians who play in ensembles. A practice mute is a comb shaped mute that is placed over all strings and is used for - you guessed it - practicing. They are a lot more sound dampening than a tourte mute.