"Eclipse" is the tenth and final track from British progressive rock band Pink Floyd's 1973 album, The Dark Side of the Moon. It was sung by Roger Waters, with harmonies by David Gilmour. After Waters left, Gilmour sang the lead when performing live. The song is often mistakenly labelled "Dark Side of the Moon" alongside "Brain Damage" because the two run together and are commonly played together on the radio, giving the impression that they are one song. The incorrect title is derived from a recurring lyric in "Brain Damage" and the title of the album. The song serves as a climax to the album and features a loud, repetitive melody which builds and then ends with a very quiet outro. When the main instrumentation ends at approximately 1:30, the sound of a heartbeat from the first track, "Speak to Me", appears and gradually fades to silence. The song consists of a repeating four chord pattern: D Major, D over C in the bass (a compound chord usually notated as "D/C".), B-flat Major Seventh ("B♭maj7" -- this chord can be heard as a D minor over a B♭ bass, or "Dm/B♭", though that is not a proper chord name), and A7 (with a suspended fourth resolving to the major third -- notated as A7sus4 to A7). However, the arrangement adds variety. Guitarist David Gilmour recorded two tracks of rhythm guitar, playing arpeggios, one in open position, and one much higher, around the tenth fret. The lower-pitched guitar part includes the open G and E strings during the B♭maj7, resulting in an added sixth and a dissonant augmented fourth. However, these notes become consonant as they sustain through to the next chord, A7. The quartet of female background singers vary their parts, rising in volume, and echoing some of Waters' lyrics, as the piece builds in intensity. On the last repetition of the chord progression, the B♭maj7 leads directly to a climax on D major, resulting in a "brightening" effect (known as the Picardy third), as the aforementioned implication of D minor in the B♭maj7 chord shifts to the major. At the end of "Eclipse", after or during the spoken words of 'There is no dark side...', a small chamber string orchestra can be heard playing a light tune which sounds like it's heard from a small radio in another room. To be able to hear this, one must listen especially carefully with headphones and the volume at maximum level. On some copies of the album, an orchestral version of The Beatles' song "Ticket to Ride" can be heard playing in the background during the fade but only on one stereo channel. Fans have tried to find a meaning behind this, but it was likely just an artefact of the recording process, such as an improperly erased tape. The recording has been identified by some as having come from George Martin's orchestral adaptation of the Beatles album Help!. Coincidentally, Paul McCartney and Wings were recording in the same studio. McCartney was one of the people interviewed by Roger Waters as part of the latter's efforts to develop dialogue to accompany certain songs on the album. The McCartney interview was not used, but Abbey Road Studios doorman Gerry O'Driscoll's was. His full answer to the question "What is 'the dark side of the moon'?", part of which is heard in "Eclipse", was: "There is no dark side of the moon, really. Matter of fact, it's all dark. The only thing that makes it look alight is the sun."
