In audio engineering

Audio engineering

An audio engineer, also called audio technician, audio technologist or sound technician, is a specialist in a skilled trade that deals with the use of machinery and equipment for the recording, mixing and reproduction of sounds. The field draws on many artistic and vocational areas, including...

, a fade is a gradual increase or decrease in the level of an audio signal

Audio signal

An audio signal is an analog representation of sound, typically as an electrical voltage. Audio signals may be synthesized directly, or may originate at a transducer such as a microphone, musical instrument pickup, phonograph cartridge, or tape head. Loudspeakers or headphones convert an electrical...

. The term can also be used for film cinematography or theater lighting, in much the same way (see fade (filmmaking) and fade (lighting)

Fade (lighting)

In stage lighting, a fade is a gradual increase or decrease of the intensity of light projected onto the stage. The term fade-in refers to gradually changing the lighting level from complete darkness to a predetermined lighting level. A fade-out refers to gradually decreasing the intensity of...

).

A recorded

Recording

Recording is the process of capturing data or translating information to a recording format stored on some storage medium, which is often referred to as a record or, if an auditory medium, a recording....

 song

Song

In music, a song is a composition for voice or voices, performed by singing.A song may be accompanied by musical instruments, or it may be unaccompanied, as in the case of a cappella songs...

 may be gradually reduced to silence at its end (fade-out), or may gradually increase from silence at the beginning (fade-in). For example, the songs "Bitter Sweet Symphony

Bitter Sweet Symphony

"Bitter Sweet Symphony" is a song by English alternative rock band The Verve, the lead track on their third album, Urban Hymns. It is based on music from an Andrew Loog Oldham adaptation of a Rolling Stones song, "The Last Time". It was released on 16 June 1997 by Hut Recordings as the first single...

" by The Verve

The Verve

The Verve were an English rock band formed in 1989 in Wigan by lead vocalist Richard Ashcroft, guitarist Nick McCabe, bassist Simon Jones, and drummer Peter Salisbury. Guitarist and keyboardist Simon Tong later became a member. Beginning with a psychedelic sound indebted to shoegazing and space...

 and "Turn to Stone

Turn to Stone

"Turn to Stone" is a 1977 song by Electric Light Orchestra.The song is the opening track to the double album Out of the Blue. It was the first song released as a single from the LP. The single reached #18 in the U.K. charts and stayed there for 12 weeks. Out of four singles from the album, "Turn to...

" by Electric Light Orchestra

Electric Light Orchestra

Electric Light Orchestra were a British rock group from Birmingham who released eleven studio albums between 1971 and 1986 and another album in 2001. ELO were formed to accommodate Roy Wood and Jeff Lynne's desire to create modern rock and pop songs with classical overtones...

 fade in from the beginning, while the songs "Born to Be Wild

Born to Be Wild

"Born to Be Wild" is a rock song written by Mars Bonfire and made famous by the Canadian-American rock band Steppenwolf. It is often used in popular culture to denote a biker appearance or attitude...

" by Steppenwolf

Steppenwolf (band)

Steppenwolf are a Canadian-American rock group that was prominent in the late 1960s. The group was formed in 1967 in Los Angeles by vocalist John Kay, guitarist Michael Monarch, bassist Rushton Moreve, keyboardist Goldy McJohn and drummer Jerry Edmonton after the dissolution of Toronto group The...

, "Boogie Oogie Oogie

Boogie Oogie Oogie

"Boogie Oogie Oogie" is the name of a popular song by disco/R&B group A Taste of Honey. Released from their self-titled album in 1978, it became an extremely popular "crossover" song. The lyrics urge listeners to "boogie oogie oogie till you just can't boogie no more." It topped the Billboard Hot...

" by A Taste of Honey

A Taste of Honey (band)

A Taste of Honey was the name of an American recording act, formed in 1971 by associates Perry Kibble and Donald Ray Johnson. In 1978 they had one of the best known chart-toppers of the disco era, "Boogie Oogie Oogie"...

, and "Hey Jude

Hey Jude

"Hey Jude" is a song by the English rock band The Beatles, written by Paul McCartney and credited to Lennon–McCartney. The ballad evolved from "Hey Jules", a song widely accepted as being written to comfort John Lennon's son, Julian, during his parents' divorce—although this explanation is not...

" by The Beatles

The Beatles

The Beatles were an English rock band, active throughout the 1960s and one of the most commercially successful and critically acclaimed acts in the history of popular music. Formed in Liverpool, by 1962 the group consisted of John Lennon , Paul McCartney , George Harrison and Ringo Starr...

 fade out. However, "Born to be Wild" and "Boogie Oogie Oogie" fade out in a matter of seconds, whereas "Hey Jude" takes over 2 minutes to completely fade out. "Goodbye Stranger

Goodbye Stranger

"Goodbye Stranger" is a song by Supertramp, which first appeared on their 1979 album Breakfast in America.The main "body" of the song is backed by a simple Wurlitzer electric piano melody; the arrangement intensifies as the song progresses. This is eventually joined by intermittent electric guitar...

" by Supertramp

Supertramp

Supertramp are a British rock band formed in 1969 under the name Daddy before renaming to Supertramp in early 1970. Though their music was initially categorised as progressive rock, they have since incorporated a combination of traditional rock and art rock into their music...

 takes about a minute to fade out. Fading-out can serve as a recording solution for pieces of music that contain no obvious ending.

Though relatively rare, some songs fade out, then fade back in. Some examples of this are "Helter Skelter" and "Strawberry Fields Forever

Strawberry Fields Forever

"Strawberry Fields Forever" is a song by The Beatles, written by John Lennon and attributed to the Lennon–McCartney songwriting partnership. It was inspired by Lennon's memories of playing in the garden of a Salvation Army house named "Strawberry Field" near his childhood home."Strawberry Fields...

" by The Beatles

The Beatles

The Beatles were an English rock band, active throughout the 1960s and one of the most commercially successful and critically acclaimed acts in the history of popular music. Formed in Liverpool, by 1962 the group consisted of John Lennon , Paul McCartney , George Harrison and Ringo Starr...

, "Suspicious Minds

Suspicious Minds

"Suspicious Minds" is a song written by American songwriter Mark James that, after the failure of his own recording, was handed to Elvis Presley by producer Chips Moman becoming one of his most notable hits and a number one in 1969, "Suspicious Minds" was widely regarded as the single that returned...

" by Elvis Presley

Elvis Presley

Elvis Aaron Presley was one of the most popular American singers of the 20th century. A cultural icon, he is widely known by the single name Elvis. He is often referred to as the "King of Rock and Roll" or simply "the King"....

, "Thank You

Thank You (Led Zeppelin song)

"Thank You" is a song written by Robert Plant and Jimmy Page that was released by English rock band Led Zeppelin on their 1969 album Led Zeppelin II.-Overview:...

" by Led Zeppelin

Led Zeppelin

Led Zeppelin were an English rock band, active in the late 1960s and throughout the 1970s. Formed in 1968, they consisted of guitarist Jimmy Page, singer Robert Plant, bassist/keyboardist John Paul Jones, and drummer John Bonham...

, "Undercover of the Night

Undercover of the Night

"Undercover of the Night" is the lead track and first single from English rock and roll band The Rolling Stones' 1983 album Undercover.-Inspiration and recording:...

" by The Rolling Stones

The Rolling Stones

The Rolling Stones are an English rock band, formed in London in April 1962 by Brian Jones , Ian Stewart , Mick Jagger , and Keith Richards . Bassist Bill Wyman and drummer Charlie Watts completed the early line-up...

, and "Bop Gun (Endangered Species)

Bop Gun (Endangered Species)

"Bop Gun " is a song by the funk band Parliament, the lead track on their 1977 album Funkentelechy Vs. the Placebo Syndrome. It was released as the album's first single. The song's lead vocal is performed by Glen Goins, his last performance on a P-Funk record.The Bop Gun is an imaginary weapon that...

" by Parliament

Parliament (band)

Parliament was a funk band most prominent during the 1970s. It and its sister act Funkadelic, both led by George Clinton, began the funk music culture of that decade.-History:...

. The Smiths

The Smiths

The Smiths were an English alternative rock band, formed in Manchester in 1982. Based on the song writing partnership of Morrissey and Johnny Marr , the band also included Andy Rourke and Mike Joyce...

' song "Some Girls Are Bigger Than Others

Some Girls Are Bigger Than Others

"Some Girls Are Bigger Than Others" is a song by The Smiths, recorded in autumn 1985 and first released on their 1986 album The Queen Is Dead. It was also released as a single in Germany.-Composition and recording:...

" features a fade-out in its intro section before fading back in.

The term fade is also used in multi-speaker audio systems to describe the balancing of power between front and rear channels.

Origins and early examples

"Neptune," part of the orchestral suite The Planets

The Planets

The Planets, Op. 32, is a seven-movement orchestral suite by the English composer Gustav Holst, written between 1914 and 1916. Each movement of the suite is named after a planet of the Solar System and its corresponding astrological character as defined by Holst...

, written by Gustav Holst

Gustav Holst

Gustav Theodore Holst was an English composer. He is most famous for his orchestral suite The Planets....

 between 1914 and 1916, was the first piece of music to have a fade-out ending. Holst stipulates that the women's choruses are "to be placed in an adjoining room, the door of which is to be left open until the last bar of the piece, when it is to be slowly and silently closed", and that the final bar (scored for choruses alone) is "to be repeated until the sound is lost in the distance". Although commonplace today, the effect bewitched audiences in the era before widespread recorded sound—after the initial 1918 run-through, Holst's daughter Imogen

Imogen Holst

Imogen Clare Holst, CBE was a British composer and conductor, and sole child of composer Gustav Holst.Imogen Holst was brought up in west London and educated at St Paul's Girls' School, where her father was director of music...

 (in addition to watching the charwomen dancing in the aisles during "Jupiter") remarked that the ending was "unforgettable, with its hidden chorus of women's voices growing fainter and fainter... until the imagination knew no difference between sound and silence".

The technique of ending a spoken or musical recording by fading out the sound goes back to the earliest days of recording. In the era of mechanical (pre-electrical) recording, this could only be achieved by either moving the sound source away from the recording horn, or by gradually reducing the volume at which the performer/s were singing, playing or speaking. With the advent of electrical recording, smooth and controllable fadeout effects could be easily achieved by simply reducing the input volume from the microphones using the fader on the mixing desk.

No single recording can be reliably identified as "the first" to use the technique. In 2003, on the (now-defunct) website Stupid Question, John Ruch listed the following recordings as possible contenders:

Contemporary

More recently: "For Henri Lefebvre (1971a:19), 'everyday life in the modern world' is a privileged site for the crucial fact of recurrence. The question of how to end a song now becomes pressing. The answer, often, is not to end: the harmonically inconclusive or artificially abrupt finish, or - quintessentially - the fade. As Sean Cubitt points out (1984: 210), this refers us"
"At the meta-song level, the prevalence of pre-taped sequences (for shops, pubs, parties, concert intervals, aircraft headsets) emphasizes the importance of flow. The effect on radio pop programme form [are] a stress on continuity achieved through the use of fades, voice-over links, twin-turntable mixing and connecting jingles."

Fader

A fader is any device used for fading, especially when it is a knob or button that slides along a track or slot. A knob which rotates is usually not considered a fader, although it is electrically and functionally equivalent. A fader can be either analogue

Analog signal

An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...

, directly controlling the resistance

Electrical resistance

The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...

 or impedance

Electrical impedance

Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...

 to the source (e.g. a Potentiometer

Potentiometer

A potentiometer , informally, a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used , it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on...

); or digital

Digital

A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...

, numerically controlling a digital signal processor

Digital signal processor

A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...

 (DSP). A fader can also be used as a control for a voltage controlled amplifier

Variable-gain amplifier

A variable-gain or voltage-controlled amplifier is an electronic amplifier that varies its gain depending on a control voltage .VCAs have many applications, including audio level compression, synthesizers and amplitude modulation....

, which has the same effect on the sound as any other fader, but the audio signal does not pass through the fader itself. Digital faders are also referred to as virtual faders, since they can be viewed on the screen of a digital audio workstation

Digital audio workstation

A digital audio workstation is an electronic system designed solely or primarily for recording, editing and playing back digital audio. DAWs were originally tape-less, microprocessor-based systems such as the Synclavier and Fairlight CMI...

. Modern high end digital mixers often feature "flying faders", faders with piezo-electric actuators attached; such faders can be multi-use and will jump to the correct position for a selected function or saved setting. Flying faders can be automated, so that when a timecode is presented to the equipment, the fader will move according to a previously performed path.

Crossfading

A crossfader on a dj mixer

DJ mixer

A DJ mixer is a type of audio mixing console used by disc jockeys.The key features that differentiate a DJ mixer from other types of audio mixers are the ability to redirect a non-playing source to headphones and the presence of a crossfader, which allows for an easier transition between two sources...

 essentially functions like two faders connected side-by-side, but in opposite directions. It allows a DJ to fade one source out while fading another source in at the same time. This is extremely useful when beatmatching

Beatmatching

Beatmatching is a disc jockey technique of pitch shifting or timestretching a track to match its tempo to that of the currently playing track e.g. the kicks and snares in two house records hit at the same time when both records are played simultaneously...

 two sources of audio (or more, where channels can be mapped to one of the two sides of the crossfader individually) such as phonograph

Phonograph

The phonograph record player, or gramophone is a device introduced in 1877 that has had continued common use for reproducing sound recordings, although when first developed, the phonograph was used to both record and reproduce sounds...

 records, compact discs or digital sources.

The technique of crossfading is also used in audio engineering as a mixing technique, particularly with instrumental solos

Solo (music)

In music, a solo is a piece or a section of a piece played or sung by a single performer...

. A mix engineer will often record two or more take

Take

A take is a single continuous recorded performance. The term is used in film and music to denote and track the stages of production.-Film:In cinematography, a take refers to each filmed "version" of a particular shot or "setup"...

s of a vocal or instrumental part and create a final version which is a composite of the best passages of these takes by crossfading between each track.

In the perfect case the crossfader would keep constant output level. However, there's no standard on how this should be achieved. Many DJ equipment manufacturers offer different mixers for different purposes (e.g. scratching, beatmixing, cut mixing, etc.). High-end mixers often have crossfade curve switches allowing the DJ to select the type of crossfade necessary. Experienced DJs are also able to crossfade between tracks using the channel faders.

There are many software applications that feature virtual crossfaders. For instance, burning

Optical disc authoring

Optical disc authoring, including DVD and Blu-ray Disc authoring , is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded onto an optical disc .-Process:To burn an optical disc, one usually first creates an...

-software for the recording of audio-CDs.

Pre-fader, post-fader

On a mixer with auxiliary send mixes, the send mixes are configured pre-fader or post-fader.

If a send mix is configured pre-fader, then changes to the main channel strip fader does not affect the send mix. In live sound reinforcement, this is useful for stage monitor mixes where changes in the Front of House

Front of House

Front of house is primarily a theatrical term, referring to the portion of the building that is open to the public. In theatre and live music venues, it typically refers to the auditorium and foyer, as opposed to the stage and backstage areas...

 channel levels would distract the musicians. In recording and post production, configuring a send to be pre-fader allows the amount of audio sent to the aux bus to remain unaffected by the individual track fader.

If a send mix is configured post-fader, then the level sent to the send mix follows changes to the main channel strip fader. This is useful for reverberation and other signal processor

Signal processor

A signal processor is an electronic circuit that removes information from an analog signal as quantifiable units for further analysis. Most modern signal processors are either dedicated microprocessor integrated circuits or general-purpose programmable microprocessors. A DSP is an electronic...

effects.