" Echoes " is a composition by Pink Floyd including fully extended instrumental passages, continuous sound effects, and musical improvisation. Written in 1970 by all four members of the group, "Echoes" provides the extended finale to Pink Floyd's album Meddle . The track has a running time of 23:31 and comprises the entire second side of the vinyl and cassette recordings. 
It also appears in shortened form as the fifth track on the compilation album which took its name, Echoes: The Best of Pink Floyd . The composition was originally assembled from separate fragments, and was later split in two parts to serve as both the opening and closing numbers in the band's film Live at Pompeii . The song was used to open the band's 1987 A Momentary Lapse of Reason Tour after not being played for over a decade, but was retired again after 11 shows. It was revived for Gilmour's 2006 On an Island Tour, where it was performed at every show. Live versions were released on Gilmour's albums Live in Gdańsk and Remember That Night .
Each verse of the song follows a pattern of three strophes.
The composition uses many progressive and unconventional musical effects. The ping sound heard at the beginning of the song was created as the result of an experiment very early in the Meddle sessions. It was produced through amplifying a grand piano, played by Richard Wright, and sending the signal through a Leslie speaker and a Binson Echorec.
David Gilmour used a slide guitar for certain sound effects on the studio recording and for the introduction in live performances from 1971 to 1975. A throbbing wind-like sound was created by Roger Waters vibrating the strings of his bass guitar with a steel slide and feeding the signal through an Echorec. The high-pitched electronic "screams", resembling a distorted seagull song, were discovered by Gilmour when the cables were accidentally reversed to his wah pedal. After observing the song being created, Nick Mason noted: "The guitar sound in the middle section of 'Echoes' was created inadvertently by David plugging in a wah-wah pedal back to front. Sometimes great effects are the results of this kind of pure serendipity, and we were always prepared to see if something might work on a track. The grounding we'd received from Ron Geesin in going beyond the manual had left its mark." Harmonic "whistles" can be heard produced by Richard Wright pulling certain drawbars in and out on the Hammond organ. Rooks were added to the music from a tape archive recording (as had been done for some of the band's earlier songs, including " Set the Controls for the Heart of the Sun "). The second half of the song, where Gilmour plays muted notes on the guitar over Wright's slowly building Farfisa organ solo, was inspired by the Beach Boys song " Good Vibrations ".  
The "choral"-sounding segment at the end of the song was created by placing two tape recorders in opposite corners of a room; the main chord tapes of the song were then fed into one recorder and played back while at the same time recording. The other recorder was then also set to play what was being recorded; this created a delay between both recordings, heavily influencing the structure of the chords while at the same time giving it a very "wet" and "echoey" feel.
The piece had its genesis in a collection of separate musical experiments written by the band, some of which had been left over from previous sessions. The group then arranged the pieces in order to make a coherent 23-minute piece originally referred to as "Nothing, Parts 1–24". Not all of the pieces were used for the finished track, and out-takes included saying a phrase backwards, so it would sound correct yet strange when the tape was reversed. Subsequent tapes of work in progress were labelled "The Son of Nothing" and "The Return of the Son of Nothing"; the latter title was eventually used to introduce the as-yet unreleased work during its first live performances in early 1971. Studio recording was split between Abbey Road Studios, Morgan Studios and AIR Studios in London; the latter two were used because they had a 16-track recorder, which made assembling the individual components of the songs easier.
In an interview in 2008 with Mojo , when asked who had composed "Echoes", Wright stated he had composed the long piano intro and the main chord progression of the song. In the same interview he confirmed that Waters wrote the lyrics. During this stage of its development, the song's first verse had yet to be finalised. It originally referred to the meeting of two celestial bodies. The first verse originally took words from Muhammad Iqbal's poem "Two Planets", and later this was rewritten with the incorporation of original underwater imagery instead.
The title "Echoes" was also subjected to significant revisions before and after the release of Meddle : Waters, a devoted football fan, proposed that the band call its new piece "We Won the Double" in celebration of Arsenal's 1971 victory, and during a 1972 tour of Germany he jovially introduced it on two consecutive nights as "Looking Through the Knothole in Granny's Wooden Leg" (a reference to The Goon Show ) and The Dam Busters , respectively.
The song was performed for Live at Pompeii , where it was split in two halves to open and close the film. The 1974 and 1975 performances featured backing vocals by Venetta Fields and Carlena Williams and saxophone solos by Dick Parry instead of the guitar solos in the 1971–73 performances (apart from the first show of the US 1975 tour, where Gilmour does the first middle solo then gives way to Parry's sax).
It was performed eleven times on the band's 1987 A Momentary Lapse of Reason world tour, in a slightly rearranged version trimmed down to 17 minutes. It was then dropped as the band were not happy with the performances.
Gilmour resurrected the song on his 2006 On an Island tour as the closing number of the main set. He sang the low parts together with Wright, while touring keyboardist Jon Carin sang the higher parts. Wright would bring the Farfisa out of retirement just for this song for the tour. These performances appear on Gilmour's Remember That Night DVD/Blu-ray and Live in Gdańsk album/DVD.
Gilmour told Rolling Stone in 2016 upon returning to Pompeii to play a solo show that he would have loved to perform "Echoes" but felt he could not do so without Wright, who had died in 2008 – "There's something that's specifically so individual about the way that Rick and I play in that, that you can't get someone to learn it and do it just like that." 
In a review for the Meddle album, Jean-Charles Costa of Rolling Stone gave "Echoes" a positive review.  Costa described "Echoes" as "a 23-minute Pink Floyd aural extravaganza that takes up all of side two, recaptures, within a new musical framework, some of the old themes and melody lines from earlier albums."  Costa further went on: "All of this plus a funky organ-bass-drums segment and a stunning Gilmour solo adds up to a fine extended electronic outing." 
Echoes and 2001: A Space Odyssey synchronisation rumours
Similar to the Dark Side of the Rainbow effect, at-large rumours suggested that "Echoes" coincidentally synchronises with Stanley Kubrick's 1968 film 2001: A Space Odyssey , when played concurrently with the final 23-minute segment titled "Jupiter and Beyond the Infinite". At the time of the film's production in 1967–1968, Pink Floyd was not working on any material suitable for the film, nor were they contacted about supplying music. It is likely that Kubrick never heard the band's music until after the film was finished. 
The 1973 George Greenough film Crystal Voyager concludes with a 23-minute segment in which the full version of "Echoes" accompanies a montage of images shot by Greenough from a camera mounted on his back while surfing on his kneeboard.
In interviews promoting Amused to Death , Waters claimed that Andrew Lloyd Webber had plagiarised the riff from "Echoes" for sections of the musical The Phantom of the Opera ; nevertheless, he decided not to file a lawsuit regarding the matter. He said:
Yeah, the beginning of that bloody Phantom song is from Echoes . *DAAAA-da-da-da-da-da*. I couldn't believe it when I heard it. It's the same time signature —it's 12/8—and it's the same structure and it's the same notes and it's the same everything. Bastard. It probably is actionable. It really is! But I think that life's too long to bother with suing Andrew fucking Lloyd Webber. 
British musician Ewan Cunningham covered "Echoes" in a YouTube video which featured him playing all of the parts himself. This cover was heavily based on the Live at Pompeii version and went on to receive praise from Nick Mason.  
- David Gilmour – lead vocals (lower harmony), electric guitars, sound effects
- Richard Wright – lead vocals (higher harmony), grand piano (through Leslie 145 speaker), Hammond organ, Farfisa organ, sound effects
- Roger Waters – bass guitar, slide bass, sound effects
- Nick Mason – drums, percussion, sound effects