nd free the picking hand to be more mobile. The popular Rickenbacker 4001 and 4003 model electric bass guitars, along with earlier model Music Man basses, also have adjustable string mutes integrated into their bridge/tailpiece assemblies, which can be used to give the instrument a more percussive sound or to simulate the shorter sustain of an upright bass. Other electric basses have mutes built into their bridge covers.
A variety of mutes have been used on brass instruments, most of which either squeeze inside the bell of the instrument, or are hung or clipped to the outside of the bell. These mutes are typically made out of aluminum, brass, or copper metal, but more economical plaster, cardboard, and plastic versions exist. Each material produces a distinctive sound. Mutes can take advantage of this by using materials like cane, leather, and steel.
Mutes will usually make the instrument play sharp. High quality mutes try to reduce intonation issues while maintaining the characteristic sound. Even so, it is often necessary for the musician to accommodate by adjusting the tuning slide, or their own aperture.
The most common type is the straight mute, a hollow, cone-shaped mute that fits into the bell of the instrument. This results in a more metallic, sometimes nasal sound, and when played at loud volumes can result in a very piercing note. Straight mutes have small pieces of cork attached to the end that squeeze against the inside of the bell and hold the mute in place. Straight mutes are available for all brass instruments, including the tuba.
The second most common brass mute is the cup mute. Cup mutes are similar to straight mutes, but have a cup portion attached to the end of the mute's cone. This allows the sound to bounce back towards the instrument bell before making its way through the gap between the cup and bell, producing a more muffled darker tone. Traditionally, cup mutes are made from fiber materials and have a very distinctive sound. Cup mutes can be made from metal, plastic or fiber materials. Some metal cup mutes have an adjustable cup portion which can be moved towards or away from the brass instrument bell to further color the tone. Newer cup mutes like the Soulo cup mute now offer an adjustable cup portion although made from a fiber composite material, allowing the user to adjust the cup while preserving the traditional cup mute sound.
The solo-tone mute (labeled by the Humes and Berg Corporation as the "Clear-Tone" mute) is shaped like a long straight mute, and includes sound baffles inside the mute that accentuate treble frequencies. It is rarely written for today but was common in jazz ensemble music written between 1930 and 1950. The most trademark use of the solo-tone mute was in Tommy Dorsey's trombone solo in "Song of India", recorded January 1, 1937.
The buzz-wah mute is shaped like a cup but is designed with vibrating membranes on the mute, as if several kazoos were attached to the instrument. This mute creates a very unusual and recognizable sound, but is quite difficult to play, and is extremely rare in performance. In the early 1920s, Joe "King" Oliver was known to hold a kazoo in the bell of his cornet to achieve the buzz effect. Commercial versions of this type of mute soon followed. The earliest version of this was the "Humes Jazzer" patented by Guy B. Humes in the mid-1920s.
The Wah-wah mute (also known by the brand name Harmon) is a hollow, bulbous mute in two parts. Unlike the more common straight or cup mutes, the Harmon mute has a solid ring of cork that completely blocks all of the air leaving the bell, and forces all of the instrument's air column into the mute. In a hole on the front of the mute, there is a cup on a tube that can be slid in or out, or removed completely, depending on the composer's direction or the player's preference. When this mute is used, the instrument produces a tinny, shallow sound which become more so . Harmon mutes are available for many brass instruments, but are only commonly used by trumpets and trombones.
Bucket mutes attach to the rim of the bell 