The album, produced by Island owner Chris Blackwell at his Berkshire farm, was recorded with myriad musicians, including Steve Winwood, Danny Thompson, John Stevens, Hansford Rowe and Rico.

The record features a relaxing, echoing sound with usage of Martyn's distinctive Echoplex guitar effects, while his lyrics discuss love, specific people and his disintegrating marriage.

"[7] The trip has been seen as a busman's holiday, as the artist socialised with reggae musicians Burning Spear, Max Romeo and Lee "Scratch" Perry, the latter of whom co-wrote the One World song "Big Muff" with Martyn.

[11] Despite Martyn's general low sales, Blackwell did not lose faith in him, having started to view him as "more of a jazz artist", and offered to produce One World, a comeback record for the singer.

[14] Although Martyn had said he brought his wife and children to the cottage,[16] he also claimed that Beverley did not attend the sessions and felt she may have erroneously thought he was living a hedonistic lifestyle at the farm.

[12] As an engineer, Brown had developed the idea of outdoor recording when working with Murray Head in 1973, but it was when using these techniques on Robert Palmer's Pressure Drop (1975) that he inspired Blackwell.

[7] Blackwell booked a large array of musicians to play on One World, resulting in what biographer Daryl Easlea compared to an "underground supergroup" with members and ex-members of Gong, Fairport Convention, Pentangle, Brand X, John Stevens Away, Gilgamesh and Traffic,[7] among them Martyn's regular collaborators Danny Thompson, Steve Winwood, Dave Pegg, John Stevens and Kesh Sathie.

[14] "Recorded mostly outdoors by a Berkshire lake, a watery spaciousness haunts grooves never cluttered despite a support cast including Lee Perry, ska trombonist Rico Rodriguez, Steve Winwood and most of Traffic among a score of musos from the Island family."

"[27] Martyn's lyrics, which highlight universal themes of love and people and occasionally social commentary,[25] were described by journalist Monty Smith as "sensitive, sly, obsessional and elliptical, but always passionate.

[7] Among the gentler songs, the title track is ethereal in style with febrile guitar, multitracked flutes and a walking bass line,[13][18] eventually fading with a breathy wail.

[15] Described by critic Vivien Goldman as resembling "a new musical form, jazz-dub", the song's reverb-heavy guitar serves as counterpoint to soft funk bass, while Moog synthesiser phases from left to right.

[26][30] Munro said the track's bossa nova feel likely harked back to Martyn's days with session musicians Mike Kowalski and Ed Carter, who had introduced him to Latin music.

"[30] According to Blackwell, the song was recorded outdoors in the early hours, with the sound of geese audible in the background,[12] as well as a passing train at the two-and-a-half minute mark, according to Martyn.

[32][33] The sleeve, designed by Tony Wright, depicts a mermaid rising from the ocean in an arc, with sea creatures trailing behind her alongside several cultural symbols.

[34] On 20 November, when playing at the Rainbow Theatre, London, Martyn and his backing band of Rowe, Thompson and Pierre Moerlen were joined by Steve Winwood, making his first live appearance in almost a year.

"[9] After his late 1977 tour, the musician played at the Collegiate Theatre, London on 10 January 1978; the performance was filmed by the BBC for a special edition of The Old Grey Whistle Test dedicated to introducing Martyn's music to a wider audience.

[12] In a review for Record Mirror, Mary Ann Ellis praised it as a "beautiful album with an ability to touch you with a lazy line or high/low note," adding that its sensitive, sincere nature would prevent it from selling well, but "[s]omehow I wouldn't want it to.

similarly said the album – with its "private territory" feel – was not radio friendly, despite the short lengths of four songs and appearances from Winwood, Newmark and Fairport Convention's rhythm section.

Describing Martyn's style as a mix of blues, jazz and rock, he hailed One World for being "as blotto and as blessed with sometimes hazy, sometimes crystalline music, as anything he's ever done," drawing comparisons with Bessie Smith, Hoagy Carmichael and Skip James.

"[13] Mark Prendergast of Melody Maker commented that Martyn "seems fated to inspire madness and mayhem, no matter how utterly shambolic the circumstances he finds himself in," feeling this may be due to his uniquely "foggy" voice and ability to "trick out what are invariably simple songs with ravishing detail.

[19] Dave Belbin of Gongster described the album as very warm and "full-sounding", comparable to "an armchair before an open fire, somewhat stoned, keeping the cold winter at bay.

"[30] In an article for Liverpool Echo, Chris Salewicz said the "strong and very worthwhile" One World features a more brittle and creative side to Martyn's "always powerful emotions and moods.

[44] Among retrospective reviews, Wilson Neate of AllMusic felt that the "electrified swagger" of "Big Muff" was the highlight of the pop-leaning songs, while finding the album's "understated explorations of mood" to be even more compelling, particularly citing the title track and "Small Hours" for their "mesmerizing, smoky grooves".

[29] In The Great Rock Discography, Martin C. Strong said that One World was, despite Martyn's increasing fan base in 1977, as "esoteric as ever" with its influences from dub and "oblique ambience.

"[41] Nick Dale listed the "pretty drugged-out record" among Martyn's essential albums in Rock: The Rough Guide, saying it contained some of the musician's most powerful and enduring songs, and highlighting the guitar effects and overall "wonderful echoing and meditative soundscape".

[21][45][46] Due to its dubby, "echoing soundscapes"[47] and experimental nature,[48][49] One World has been cited as originating trip hop music,[47][48][49] which emerged in earnest in the 1990s with groups like Portishead,[47] whom Martyn later covered.

[48] "Smiling Stranger" has been described as a forerunner to the sound of Massive Attack and was called "one of the great moments in dub" by world music pioneer Jah Wobble.

[7] In The Guardian, Reynolds credited "Small Hours" for anticipating the Durutti Column, feeling this possibly exemplified Factory Records's "hippy-dippy side" – the staff had been fans of Martyn – for returning "after the rupture of punk".

[37] In his liner notes for the reissue, Easlea credits the album's sonic developments, namely being able to operate a live feed across a lake so sessions could be taped in the open air, "picking up the full ambience of the surroundings", as an innovation which would prove as important as Giorgio Moroder's contemporary production of "I Feel Love" by Donna Summer.