Many different types of trombone mutes are available to players, including bucket mutes, straight mutes, cup mutes, harmon mutes, and plunger mutes. These are the most common types of trombone mutes, but others, such as the derby hat mute and the practice mute, are also available. The mute changes the sound produced by the trombone, and this can be done in a variety of ways. Sound produced by the instrument is muffled slightly, but generally the shape and material used to make the mute alters the sound in a specific way. The practice mute is the only type of mute designed solely to make the instrument quieter.
Straight mutes are some of the most common trombone mutes. These are slightly conical in shape, with an opening at the thinner end and a closed thicker end. Cardboard and aluminum are the two most common materials used to make a straight mute, and these produce slightly different sounds. The aluminum version of the mute creates a bright, biting tone and the cardboard variety creates a more muffled and stuffy tone. The thinner end of the mute is placed into the bell of the trombone.
Harmon mutes are also often called “wah wah” mutes because they can be used to make a sound akin to a person saying “wah wah.” These trombone mutes are made out of aluminum and consist of a large bell-shaped piece and a thin stem. The stem is inserted into the bell of the trombone and the larger section is placed on top of it. Players cover and uncover the end of the harmon mute to create a “wah wah” sound. Some players, such as Miles Davis, like to use the harmon mute without the stem.
Bucket mutes are another variety of trombone mute. They are shaped like a bucket. These are unusual in that they don’t actually fit into the bell of the instrument, but are rather clipped onto the outside. The mutes are usually made from cardboard lined with cotton to muffle the sound. This is amongst the most noise-eliminating of the trombone mutes.
Cup mutes are among the other common types of trombone mutes. They are very similar to a standard straight mute. The main different is that cup mutes have a cup-shaped attachment on the thicker end of the conical straight mute. Rounded edges on the cup attachment allow some air to escape from the bell, but the sound is still muffled more than on a straight mute. Most cup mutes are made from cardboard.