[6] The album saw the group embrace a subtler folk-influenced sound based around acoustic guitars and orchestral arrangements, while primary songwriter Arthur Lee explored darker themes alluding to mortality and his growing disillusionment with the era's counterculture.

It was the final album recorded by the original band lineup; after its completion, guitarist Bryan MacLean left the group acrimoniously, and Lee subsequently dismissed the other members.

[9] However, the group's opportunity for major national success dwindled as a consequence of frontman Arthur Lee's unwillingness to tour, his deteriorating relationship with Love's other songwriter Bryan MacLean, and the overshadowing presence of label-mates the Doors.

[12] Throughout this period, the band – reduced to a quintet with the departures of Alban "Snoopy" Pfisterer and Tjay Cantrelli – were known to retreat to a dilapidated mansion in Hollywood, nicknamed "The Castle", to use heroin, causing further stagnation.

[citation needed] Rather than base his writings on Los Angeles's burgeoning hippie scene, Lee's material for Forever Changes was drawn from his lifestyle and environment.

[20] According to AllMusic, the band embraced "a more gentle, contemplative, and organic sound on Forever Changes," with much of the album "built around interwoven acoustic guitar textures and subtle orchestrations, with strings and horns both reinforcing and punctuating the melodies.

[18] Stephen M. Deusner of Pitchfork stated that Lee paired his "dark, discomfiting lyrics" with music that draws from rock, psychedelia, folk, pop, classical, and mariachi influences.

[22] To compel the band to participate, Botnick enlisted Wrecking Crew session musicians Billy Strange (guitar), Don Randi (piano), Hal Blaine (drums), and Carol Kaye (bass guitar) to work with Lee, completing the sessions for "Andmoreagain" and "The Daily Planet" in one day.

[23] Shocked by the notion of losing their roles, Botnick's plan succeeded in motivating the other Love members to participate in recording the remaining material.

Writing for Rolling Stone in 1968, Jim Bickhart regarded Forever Changes as Love's "most sophisticated album yet", applauding the orchestral arrangements and recording quality.

[26] In Esquire, Robert Christgau called it an elaboration on Love's original musical style and "a vast improvement" over their previous recordings, because "Lee has stopped trying to imitate Mick Jagger with his soft voice, and the lyrics, while still obscure, now have an interesting surface as well.

Gene Youngblood of LA Free Express also praised the album, calling it "melancholy iconoclasm and tasteful romanticism.

The album was re-released in an expanded single-CD version by Rhino in 2001, featuring alternate mixes, outtakes and the group's 1968 single, "Your Mind and We Belong Together"/"Laughing Stock", the final tracks ever to feature the Forever Changes line-up of Arthur Lee, Johnny Echols, Ken Forssi, Michael Stuart-Ware and Bryan MacLean (Forssi and MacLean both died in 1998).

The set features the entire album performed in its original running order, recorded in early 2003 during Lee's tour of England, in which he was backed by the band Baby Lemonade and members of the Stockholm Strings 'n' Horns ensemble.

A 50th anniversary deluxe edition box set was released by Rhino on April 6, 2018, featuring four CDs, a DVD and an LP.

[51] According to the New Musical Express, the Stone Roses' relationship with their future producer John Leckie was settled when they all agreed that Forever Changes was the "best record ever".