Editing Tremolo (section)

=== Amplitude variation ===
[[File:Fuse Electronics Tremolo MK-III Quick Demo.ogg|thumb|Video of a tremolo [[Effects unit|effect pedal]], producing a cycling variation of volume, played with an [[electric guitar]]]]A separate type of tremolo is a variation in [[amplitude]]:
* As produced on organs by [[tremulant]]s
* Using electronic effects in guitar amplifiers and effects pedals which rapidly turn the volume of a signal up and down, creating a "shuddering" effect
* An imitation of the same by strings in which pulsations are taken in the same bow direction
* A [[vocal technique]] involving a wide or slow [[vibrato]], not to be confused with the [[Trill (music)#Trillo|trillo]] or "Monteverdi trill"
Tremolo is sometimes used interchangeably with vibrato. However, a tremolo is a variation of volume (or amplitude); as contrasted with [[vibrato]], which is a variation of pitch (or frequency).
[[File:Fender Pro Amp brownface (1960s, pre-CBS) front panel - mid.jpg|thumb|"Vibrato" channel on a 1960s [[Fender (company)|Fender]] Pro Amp Brownface [[Guitar amplifier|electric guitar amp]]. The effect produced is actually a tremolo.]]
Some [[electric guitar]]s (in particular the [[Fender Stratocaster]]) use a lever branded a "tremolo arm"<ref name=":0">{{Cite book |last=Hunter |first=Dave |url=https://books.google.com/books?id=hVP0AwAAQBAJ&pg=PA221 |title=The Fender Stratocaster: The Life and Times of the World's Greatest Guitar and Its Players |date=2013-11-16 |publisher=Quarto Publishing Group USA |isbn=978-1-61058-878-2 |pages=221 |language=en}}</ref> or "[[whammy bar]]" that allows a performer to lower or (usually, to some extent) raise the pitch of a note or chord, an effect properly termed [[vibrato]] or "pitch bend". This non-standard misuse of the term "tremolo" refers to pitch rather than amplitude.<ref name=":0" /> However, the term "trem" or "tremolo" is still misused to refer to a [[Bridge (instrument)|bridge system]] built for a whammy bar, or the bar itself. True tremolo for an electric guitar, [[electronic organ]], or any electronic signal would normally be produced by a simple [[amplitude modulation]] [[electronic circuit]], or in terms of [[analog synthesis]], a [[Variable-gain_amplifier|VCA]] under control of an [[Low-frequency_oscillator|LFO]]. Electronic tremolo effects were available on many early [[guitar amplifier]]s. [[Fender (company)|Fender]] labeled them Vibrato, adding to the confusion between the two terms.<ref>{{Cite book |last1=Teagle |first1= John |url=https://books.google.com/books?id=kO8y6J6Is_4C&pg=PA225 |title=Fender Amps: The First Fifty Years |last2=Sprung |first2= John |date=1995 |publisher=Hal Leonard Corporation |isbn=978-0-7935-3733-4 |pages=225 |language=en}}</ref> Tremolo effects pedals are also widely used to achieve this effect.

Most settings on a tremolo effects pedal include depth of the tremolo (sometimes called intensity) and speed of the tremolo. Some models allow to choose the shape of the waveform ([[sine wave]], [[triangle wave]], [[Square wave (waveform)|square wave]]).<ref>{{Cite book |last=Hunter |first=Dave |url=https://books.google.com/books?id=sM5azHTPaQ4C&pg=PT311 |title=The Rough Guide to Guitar |date=2011-02-01 |publisher=Rough Guides UK |isbn=978-1-4053-8873-3 |pages=311 |language=en}}</ref>