A half-moon switch is a type of electronic

toggle switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...

. It is commonly used in

electronic instrument An electronic musical instrument or electrophone is a musical instrument that produces sound using electronic circuitry. Such an instrument sounds by outputting an electrical, electronic or digital audio signal that ultimately is plugged into ...

s, mainly in adjusting the

Chorale Chorale is the name of several related musical forms originating in the music genre of the Lutheran chorale: * Hymn tune of a Lutheran hymn (e.g. the melody of "Wachet auf, ruft uns die Stimme"), or a tune in a similar format (e.g. one of the t ...

and

tremolo In music, ''tremolo'' (), or ''tremolando'' (), is a trembling effect. There are two types of tremolo. The first is a rapid reiteration: * Of a single Musical note, note, particularly used on String instrument#Bowing, bowed string instrument ...

in a

Leslie speaker The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided ...

Function

In a Leslie speaker, the function of the switch is to control the speed of the oscillating horn, thus controlling frequency of the

vibrato Vibrato (Italian language, Italian, from past participle of "wikt:vibrare, vibrare", to vibrate) is a musical effect consisting of a regular, pulsating change of pitch (music), pitch. It is used to add expression to vocal and instrumental music. ...

. It ranges from slowest (labelled chorale) to fastest (labelled tremolo). There is often an off position in between the two settings, depending on the switch. Half-Moon Switch

References

Switches {{electronics-stub