Lennon wrote his portion of the song after attending the 14 Hour Technicolor Dream, an all-night festival held at London's Alexandra Palace that served as a key event in the emergence of the counterculture in the UK.

Among reviewers' varied comments on the song, Billboard admired it as "an Eastern-flavored rocker with an infectious beat and an intricate lyric",[3] while Pitchfork has dismissed it as "a second-rate take on John Lennon's money-isn't-everything theme".

[5] "Baby, You're a Rich Man" was the result of combining two unfinished songs written by Lennon and McCartney,[6] in a similar fashion to "A Day in the Life" and "I've Got a Feeling".

[11] According to author Barry Miles, who was among the leading figures in the UK underground in 1967,[12] Lennon drew inspiration for the song from newspaper articles on the emerging hippie phenomenon.

[17][nb 1] According to author and critic Ian MacDonald, Lennon was most likely inspired to write the verses after attending the 14 Hour Technicolor Dream, an all-night festival held at Alexandra Palace in north London on 29 April 1967.

[19] Writing in 1981 on the musical and societal developments of 1967, sociomusicologist Simon Frith said that this event was one of the "multi-media happenings" that reflected the new aesthetic represented by English psychedelia, whereby "Dancing became less important than listening" and fashion embraced vivid colours while retaining "the mod concern for looking smart".

[24] According to MacDonald, the song's loose, swinging rhythm, which he describes as "chugging pseudo-march", suggests the influence of the Four Tops' 1966 hit single "Reach Out I'll Be There".

[17][nb 3] Author and critic Kenneth Womack comments that the lyrics appear to "address issues of wealth and celebrity" for listeners unfamiliar with the countercultural concept of "beautiful people".

[27] The song reflects the Beatles' disdain for consumerism and materialism, a theme that, inspired by the band members' use of the hallucinogenic drug LSD, they introduced in the lyrics to Revolver tracks such as "And Your Bird Can Sing".

Authors Russell Reising and Jim LeBlanc highlight the lines "You keep all your money in a big brown bag inside a zoo / What a thing to do" as particularly dismissive of the acquisition and hoarding of material wealth.

[33] They recorded "Baby, You're a Rich Man" in a six-hour session, starting at 9 pm on 11 May, at Olympic Sound Studios in Barnes, south-west London.

[39] The music features an unusual oboe-like sound reminiscent of an Indian shehnai,[10] which was created with a clavioline,[40] an early, three-octave forerunner of the synthesizer.

[56] Spitz writes that the session tapes also reveal Lennon improvising similarly "wicked" remarks about McCartney, Ringo Starr and Jagger.

[31][67] While parts of the song were used in the film, its initial release was as the B-side of "All You Need Is Love",[68] which the Beatles performed on the Our World satellite broadcast on 25 June 1967[69] and then rush-released as a single.

Pepper, which historian David Simonelli describes as "the most important cultural moment of 1967" through its resonance "across every boundary of class, age, gender, race and geography".

[79][nb 8] In a 1970 interview, when asked about Haight-Ashbury, the district of San Francisco that represented "the city of the beautiful people" in 1967,[82] Lennon recalled that he was "all for going and living" there, but "George went over in the end.

"[83] During this visit, on 7 August, Harrison was handed an acoustic guitar in Golden Gate Park[84] and briefly performed "Baby, You're a Rich Man",[85] leading a crowd around in a manner that press reports likened to the Pied Piper of Hamelin.

[67][86] Although the visit was viewed as the Beatles' endorsement of a youth movement that they helped inspire,[84] Harrison was disappointed at how Haight-Ashbury represented a haven for dropouts and drug addicts, rather than a community looking to explore the possibility of enlightenment that LSD presented.

[91] In light of this development, author Nicholas Schaffner wrote that "Baby, You're a Rich Man", like "Strawberry Fields Forever", revealed the "redundant" aspect of repeated LSD "trips" after the initial sense of spiritual euphoria awakened by the drug, in that the songs "tend[ed] to provide more riddles than solutions".

[67] Against the Beatles' wishes, Capitol Records, EMI's North American affiliate, included "Baby You're a Rich Man" and other tracks from the band's 1967 singles on the US album Magical Mystery Tour, released in November that year.

He highlighted Lennon's falsetto singing, the recording's "Oriental instrumentation and … unusual shuffle beat, emphasised by handclaps", and concluded: "The whole effect is startling and packed with interest from the word go.

[42] In his assessment of "Baby, You're a Rich Man", Ian MacDonald welcomes the use of clavioline, saying that it evokes "a beguiling joss-stick exoticism", and he praises Starr's drumming as the equal of his performance on the song "Rain".

"[30] Writing for Mojo in 2003, Martin O'Gorman paired "Baby, You're a Rich Man" with Harrison "It's All Too Much" as two of the Beatles' "most sonically intriguing, but unfocused tracks".

[109] In a 2009 review of Magical Mystery Tour, Scott Plagenhoef of Pitchfork dismissed the song as "a second-rate take on John Lennon's money-isn't-everything theme from the considerably stronger 'And Your Bird Can Sing'".

"[110] Music critic Jim DeRogatis considers the track to be one of the Beatles' best psychedelic rock songs and an effective comment on Britain's first major countercultural happening.

[16] The magazine's editors wrote: "Lennon's deeply stoned delivery and abstract questions about 'the beautiful people' captured the playfully spaced-out mood of the summer of 1967 – a spirit the Beatles were more tapped into than anyone.

"[112] George Martin and recording engineer Geoff Emerick created the first true stereo mix of the song when preparing a 1971 German release of the Magical Mystery Tour album.

[117] Noel Murray and Matt Singer of The Dissolve include this appearance among the five most effective uses of a Beatles song in a feature film, describing it as the "perfect musical summation for The Social Network".