[5] In spite of this, the loss of Clark resulted in an album with four cover versions and an instrumental, which critics have described as "wildly uneven" and "awkward and scattered".

[8] Upon release, Fifth Dimension was widely regarded as the band's most experimental album to date and is today considered by critics to be influential in originating the musical genre of psychedelic rock.

[10][12] Melcher had guided the Byrds through the recording of their first two folk rock albums, which had included the international hit singles "Mr. Tambourine Man" and "Turn!

[15][16] While the songs "Eight Miles High" and "Captain Soul" featured the participation of Clark, the remaining nine tracks on the Fifth Dimension album were recorded without him.

[10][18] The album also included the McGuinn-penned songs "5D (Fifth Dimension)" and "Mr. Spaceman", with the latter being an early foray into country rock and a semi-serious meditation on the existence of alien life.

[5][22] In particular, Variety magazine targeted "5D (Fifth Dimension)" shortly after its release as a single, claiming that it was one of a recent spate of pop songs to include veiled drug references in its lyrics.

", began his penchant for writing abstract songs asking irresoluble questions—a trend that continued throughout his career with Crosby, Stills & Nash and as a solo artist.

[2][17][22] Author Johnny Rogan has commented that "I See You" was indicative of the Byrds' move away from the darkly-romantic songs of Clark towards material that examined psychological states.

[5] The album also includes the instrumental "Captain Soul", a song credited to all four band members that grew out of an in-studio jam of Lee Dorsey's "Get Out of My Life, Woman", and which features Clark playing harmonica.

[21] Another cover version on the album, "I Come and Stand at Every Door", has been called the most macabre song in the Byrds' oeuvre by biographer Johnny Rogan.

[21] The song's lyrics, which were adapted from a poem by Nâzım Hikmet, recount the story of a seven-year-old child who was killed in the atomic bombing of Hiroshima.

[2][21] The two traditional folk songs included on the album, "John Riley" and "Wild Mountain Thyme", were both introduced to the band by McGuinn, who had learned them via recordings made by Joan Baez and Pete Seeger respectively.

[5] Writing for the AllMusic website, critic Richie Unterberger regarded both "John Riley" and "Wild Mountain Thyme" as "immaculate folk rock", praising the arrangements.

"[26] Journalist Jon Landau, writing in Crawdaddy!, was less complimentary about the album and cited the departure of Gene Clark as a contributing factor in its artistic failure.

[26] Landau concluded by saying that the album "cannot be considered up to the standards set by the Byrds' first two and basically demonstrates that they should be thinking in terms of replacing Gene Clark instead of just trying to carry on without him.

"[26] In the UK, Disc magazine was also critical, bemoaning a lack of energy in the album's contents and commenting: "Here then are those Byrds with the fresh eager exciting music sounding like tired and disillusioned old men looking back on the happy days.

"[26] In more recent years, Richie Unterberger, writing for the AllMusic website, has described Fifth Dimension as "wildly uneven", noting that the album's short-comings prevent it "from attaining truly classic status".

[2] Despite its inconsistency, Fifth Dimension is today regarded as a highly influential, albeit transitional, album that is musically more experimental than the band's previous recorded output.

[3][5] A reviewer for Entertainment Weekly wrote in 1996 that "time hasn't enhanced the group's forays into psychedelia", yet the album contains "enough keepers to make you forgive their occasional tendency to fly into walls".

[27] Barney Hoskyns of Mojo magazine was less impressed and deemed Fifth Dimension to be a "breakthrough" work, but also one that "can't quite decide what sort of album it is".

Spaceman'), garage punk ('Hey Joe'), instrumental R&B ('Captain Soul'), folk standards ('Wild Mountain Thyme', the lovely 'John Riley'), and rallying calls to the emerging hippy youth ('What's Happening?!?!').

[2] However, Fifth Dimension actually contained fewer covers than either of their Clark-era albums, as well as an absence of songs by Bob Dylan, whose material, along with Clark's, had dominated earlier Byrds releases.

[26] In his 2003 book Eight Miles High: Folk-Rock's Flight from Haight-Ashbury to Woodstock, Unterberger regards the album as a pivotal moment in establishing the Byrds' status within the emerging counterculture.

[36] The reason for these remixes was explained by Bob Irwin (who produced these re-issues for compact disc) during an interview: The first four Byrds albums had sold so well, and the master tapes used so much that they were at least two, if not three generations down from the original.