Wah-wah (music)

[3] In 1921, trumpet player Johnny Dunn's use of this style inspired Tricky Sam Nanton to use the mute with the trombone.

Often it is controlled by movement of the player's foot on a rocking pedal connected to a potentiometer.

[6] The wah-wah effect is produced by periodically bringing in and out of play treble frequencies while a note is sustained.

Tricky Sam Nanton's wah-wah on trombone in Duke Ellington's Orchestra became well known as part of the so-called "jungle" effects of the band in the late 1920s.

[7] Although the most common method of producing wah-wah on brass instruments is with a mute, some players have used electronic filtering, notably Miles Davis on trumpet.