[2] Kesha assumed an integral role in the album's production and collaborated with several producers, including Ricky Reed, Drew Pearson, Ben Folds, and her mother Pebe Sebert.

Following the release of her second studio album, Warrior (2012), Kesha dealt with several struggles in her personal and professional life, including a stint in a treatment center for an eating disorder and emotional issues, as well as a highly publicized legal battle with her former record producer Dr. Luke, whom she accused of sexual, physical, and emotional abuse.

She co-wrote all but one track on the album, and said that she wanted her new music to reflect that she is a "real person having a complete human experience," stating that there was no balance in her previous work.

[4] Kesha stated that the album was inspired by several of her musical influences, including Iggy Pop, T. Rex, Dolly Parton, the Beatles, the Rolling Stones, the Beach Boys, James Brown, and Sweet.

Kesha initially began writing songs for her third studio album while as a patient at Timberline Knolls, an Illinois treatment center, for an eating disorder in 2014.

[4] She was not permitted to use any instrument with a power cord, explaining in an interview with Rolling Stone that the staff did not want her to have any objects that could be used for suicide: "And I was like, 'I respect all of that, but please let me have a keyboard or my brain's going to explode.

'"[5] She completed work on several songs while in treatment, and following her release from rehab, she removed the dollar sign from her name, explaining it as a way of taking back her power.

[13][14] In a New York Magazine profile in October 2016, Kesha stated that as much as her first two studio albums Animal (2010) and Warrior (2012) represented who she was, she felt there was "no balance", saying that she is "a real person having a complete human experience" and she wanted her future music to represent that: "To this day, I've never released a single that's a true ballad, and I feel like those are the songs that balance out the perception of you, because you can be a fun girl.

'"[15] Kesha has said that Rainbow was inspired by her "true" musical influences: Iggy Pop, T. Rex, Dolly Parton, the Beatles, the Rolling Stones, the Beach Boys, James Brown, and Sweet.

[27] Katie Baillie of Metro, who reviewed Rainbow a month before its release, called it a "powerful, emotional and strongly feminist record that is worth the four-year wait."

She wrote that the "vulnerability of some songs will bring a tear to your eye, while others are so close to Kesha's old sound it'll have dance floors filled everywhere in no time."

"[2] Andrew Uterberger of Billboard complimented Kesha's ability to make every song on the album sound different as well as differentiate herself from the electropop sound of her first two albums, stating that "it all works" and writing: "Kesha has the swagger for neo-glam, the grit for old-school soul, the pipes for power-balladry – listening to some of the spine-shivering feats she accomplishes on 'Praying', it's practically unthinkable that she was mostly consigned to sing-speaking her way through the majority of her musical career.

And she's not even half done: Before the end of Rainbow, the singer formerly known as K-Money will have sauntered her way through train-chugging, Johnny Cash-via-Kacey Musgraves country ('Hunt You Down'), schlocky frat rock ('Boogie Feet') and quirky singer-songwriter parables ('Godzilla').

"[38] Brittany Spanos of Rolling Stone gave Rainbow four stars out of a possible five and wrote: "On her excellent comeback record, Rainbow, Kesha channels that drama into the best music of her career – finding common ground between the honky-tonks she loves (her mom is Nashville songwriter Pebe Sebert) and the dance clubs she ruled with hits like 'Tik Tok' and 'Die Young', between glossy beats, epic ballads and grimy guitar riffs.

Rainbow is full of sympathetic (if at times cloying) prisoner metaphors and therapist clichés [...] Across the board, she achieves a careful balance of her diverse musical selves: The gospel-tinged 'Praying' takes the high road by wishing the best to the people who have hurt her, and 'Woman' is a blissfully irreverent, proudly self-sufficient retro-soul shouter backed by Brooklyn funk crew the Dap-Kings.

Kesha flips and filters it through her dreamy vision, turning the sweet tune into rousing rockabilly until the standard sounds refreshed and vividly modern, battle-tested and born again.

There's a strong, organic rock and country influence that places her much more firmly in a lineage, a tradition, instead of the weird, airless, EDM-influenced vacuum that she inhabited on songs like the title track of 2012's Warrior and hits like 'Blow'.

"[40] In an equally favorable review, Hilary Weaver of Vanity Fair described Rainbow as "a blatant, angry response to the singer's battle with a legal system that has left her feeling frustrated and trapped as an artist—but also a powerful pop album that earns the anticipation", writing: "This is an unapologetically open and honest Kesha we have never heard before—her voice is still recognizable but not as poppy and more focused with a message she wants her audience to hear loud and clear.

She seems to come closest to directly referencing Dr. Luke once, as 'the boogeyman under [her] bed' in 'Letting Go'; the album is a more general, vocal proclamation against anyone who has wronged her in the past.

This is Kesha's story, but it’s also the response that any woman in the Trump era of wikt:"locker room talk" might want to blast in her car on a particularly frustrating day."

It would be nice to report that the songs addressing the distress of the last few years reveal her as a great confessional singer/songwriter, but the clunkiness of her most sober material here blunts its impact.

"[41] Willman also lamented that the moments where Kesha expresses glimpses of her previous electropop "ridiculousness" on the album "[feel] refreshing and, just maybe, even more authentic.

Not that you'd want her to push past her pain prematurely, but when it comes to the writing part, Kesha just happens to still be cleverer at playing koo-koo than guru.