While the released version of the song was very successful, the post-production modifications to the song by producer Phil Spector angered McCartney to the point that when he made his case in court for breaking up The Beatles as a legal entity, McCartney cited the treatment of "The Long and Winding Road" as one of six reasons for doing so.
The song takes the form of a piano-based ballad, with conventional chord changes. The song's home key is in E-flat major but also uses relative minor; the key of C minor. Lyrically, it is a sad and melancholic song, with an evocation of an as-yet unrequited, though apparently inevitable, love.
The "long and winding road" of the song was claimed to have been inspired by the B842, a thirty-one mile (50 km) winding road in Scotland, running along the east coast of Kintyre into Campbeltown, and part of the eighty-two mile (133 km) drive from Lochgilphead. In an interview in 1994, McCartney described the lyric more obliquely:
The opening theme is repeated throughout, the song lacks a traditional chorus, and the melody and lyrics are ambiguous about the opening stanza's position in the song; it is unclear whether the song has just begun, is in the verse, or is in the bridge.
In May 1969, Glyn Johns, who had been asked to mix the Get Back album by The Beatles, selected the 26 January recording as the best version of the song. The Beatles had recorded a master version as part of the 'Apple studio performance' on 31 January, which had different lyrics and structure, but was not released. Bootlegs of the recording sessions of that day, and the film, show the band recording numerous takes of the song in a concerted effort to create a master. For both the 1969 and 1970 versions of the Get Back album, Glyn Johns used the 26 January mix as released on the Anthology 3 album in 1996. When the project was handed over to Phil Spector he also chose the 26 January recording. In the spring of 1970, John Lennon and The Beatles' manager, Allen Klein, turned over the recordings to Phil Spector with the hope of salvaging an album, which was then titled, Let It Be.
Spector made various changes to the songs, but his most dramatic embellishments would occur on 1 April 1970, when he turned his attention to "The Long and Winding Road". At Abbey Road Studios, he recorded the orchestral and choir accompaniment for the song. The only member of The Beatles present was Ringo Starr. Already known for his eccentric behaviour in the studio, Spector was in a peculiar mood that day, as balance engineer Pete Brown recalled: "He wanted tape echo on everything, he had to take a different pill every half hour and had his bodyguard with him constantly. He was on the point of throwing a wobbly, saying 'I want to hear this, I want to hear that. I must have this, I must have that.'" Brown and the orchestra eventually became so annoyed by Spector's behaviour that the orchestra refused to play any further, and at one point, Brown left for home, forcing Spector to telephone him and persuade him into coming back after Starr had told Spector to calm down.
Finally, Spector succeeded in remixing "The Long and Winding Road", using 18 violins, four violas, four cellos, three trumpets, three trombones, two guitars, and a choir of 14 women. The orchestra was scored and conducted by Richard Hewson, who would later work with McCartney on his album, Thrillington. This lush orchestral treatment was in direct contrast to The Beatles' stated intentions for a "real" recording when they began work on Get Back.
In an interview published by the Evening Standard in two parts on 22 April and 23 April 1970, McCartney said: "The album was finished a year ago, but a few months ago American record producer Phil Spector was called in by John Lennon to tidy up some of the tracks. But a few weeks ago, I was sent a re-mixed version of my song 'The Long and Winding Road' with harps, horns, an orchestra, and a women's choir added. No one had asked me what I thought. I couldn't believe it." The Beatles' usual producer, George Martin, agreed, calling the remixes "so uncharacteristic" of The Beatles. McCartney asked Klein to dissolve The Beatles partnership, but was refused. Exasperated, he took the case to court, naming Klein and the other Beatles as defendants. Among the six reasons McCartney gave for dissolving The Beatles was that Klein's company, ABKCO, had caused "intolerable interference" by overdubbing "The Long and Winding Road" without consulting McCartney.
Spector claimed that he was forced into remixing "The Long and Winding Road", because of the poor quality of Lennon's bass playing. While the poor quality of the bass playing has been noted by other sources (Ian MacDonald described it as "atrocious" in his Revolution in the Head, which contains editorial reviews of several Beatles songs), its basis as the full-scale re-working of the track by Spector has been questioned. McCartney has argued that Spector could have merely edited out the relevant mistakes and rerecorded them, a technique Spector used elsewhere on the album. Specifically, it would have been a simple matter of having McCartney overdub a more appropriate bass part to replace the Lennon bass line that was judged to be inadequate.
The controversy surrounding the song did not prevent a chart-topping single from being released in the United States on 11 May 1970, joined by "For You Blue" on the B-Side. 1.2 million copies were sold in the first two days, and the song began its ten-week long chart run on 23 May. On 13 June, it became The Beatles' twentieth and final number one single in America, according to Billboard magazine. "The Long and Winding Road" brought the curtain down on The Beatles' six years of domination in America, beginning with "I Want to Hold Your Hand" in 1964.
Ringo Starr was impressed with the Naked version of the song: "There's nothing wrong with Phil's strings, this is just a different attitude to listening. But it's been 30-odd years since I've heard it without all that and it just blew me away." Spector himself argued that McCartney was being hypocritical in his criticism: "Paul had no problem picking up the Academy Award for the Let It Be movie soundtrack, nor did he have any problem in using my arrangement of the string and horn and choir parts when he performed it during 25 years of touring on his own. If Paul wants to get into a pissing contest about it, he's got me mixed up with someone who gives a shit."
After its original release, "The Long and Winding Road" became a staple of Paul McCartney's post-Beatles concert repertoire. On the 1976 Wings Over the World Tour, where it was one of the few Beatles songs played, it was performed on piano in a sparse and effective arrangement using a horn section. In McCartney's 1989 solo tour and since, it has generally been performed on piano with an arrangement using a synthesiser mimicking strings, but this string sound has been much more restrained than on the Spector recorded version. McCartney also played the song to close the Live 8 concert in London.
"The Long and Winding Road" has been covered on occasion since its original release (though less so than many other Beatles ballads). Notable vocal versions were released by Diana Ross (Everything Is Everything, 1970), Kenny Rogers (1974), Olivia Newton-John (1976), Peter Frampton (with McCartney playing rhythm guitar), Cher (Half-Breed, 1973), Leo Sayer for the 1976 evanescent musical documentary All This and World War II, Aretha Franklin, Billy Ocean (Suddenly (Billy Ocean album), 1984), and Tom Jones; the song is also a popular choice for Beatles instrumental collections and has been used as Muzak. A version of the song spent two weeks at number one in the UK in 2002 as a duet by Pop Idol winner Will Young and runner-up Gareth Gates, having sold 132,500 copies in its first week of release. The song was performed in the seventh season of American Idol by finalist David Archuleta, who was praised highly by the contest judges for his rendition. One of the most popular singers in the Philippines, Regine Velasquez, also performed a cover of the song in 1999 in her album R2K.
A version of the song was recorded by Ray Charles and can be heard on the 2006 album Ray Sings, Basie Swings. This album is a posthumous release based upon a live Ray Charles and Count Basie concert in the 1970s - the sound had been recorded only through Charles's vocal microphone, leaving the band practically inaudible. In 2006, the recording was discovered and new big band parts were recorded by the present Basie band.