"Shake It Out" is a song by English indie rock band Florence and the Machine, released as the first official single from their second studio album, Ceremonials (2011).

"[3] During an interview with MTV News she described the recording process: "I think I came to the studio with a bit of a hangover, and it was one of those strange days where you're not really sure where a song comes from.

And I was thinking of regrets, like, you know when you feel like you're stuck in yourself, you keep repeating certain patterns of behavior, and you kind of want to cut out that part of you and restart yourself.

"[7] Digital Spy's Robert Copsey stated: "earthy drums are dressed with bells and tambourines before Flo chants 'Shake it out, shake it out, ooh-waaoah!'

"[8] Consequence of Sound's Alex Young concluded that the song "takes approximately 37 seconds to build up before a pulsating drum enters".

[9] AllMusic's James Christopher Monger commented that when the swelling guitars, organs, and strings, staccato percussion, and Florence Welch's "air-raid siren of a voice" start in the song, begins a "battle over which one is going to launch itself into the stratosphere first.

"[15] In his review of Ceremonials, Rob Harvilla of Spin wrote: "Consider rapturous call to arms 'Shake It Out,' a feast of droning organs and concussive drums that begins as an assassination/martyrdom attempt, throwing Flo to the clichés instead of the lions: 'It's always darkest before the dawn,' 'Damned if I do and damned if I don't,' 'At the end of my rope,' 'It's a shot in the dark,' and all-time Catholic-hymn classic 'It's hard to dance with a devil on your back.'

[19] Monte Lipman a CEO of Florence and the Machine's label, Universal Republic Records, described the song as "an anthem in every gym in America a year from now.

Two weeks after Florence and the Machine announced The Weeknd's remix through their official website, Zane Lowe's Radio 1 show debuted the song on 26 September.

[23] Spin's Marc Hogan wrote that the remix had a "predictably sultry-yet-creepy results"[24] and added that it "converts the sacred into the profane, warping Welch's distinctly pure voice and surrounding it with his signature goth-R&B slither.

Fans of Florence's uptempo original may be weirded out by the moody, heavily filtered take; meanwhile, Weeknd devotees may be a little disappointed to learn that Tesfaye doesn't sing on the track.

[30] Writing for the magazine Dose, Leah Collins compared the song with the band's previous single "What the Water Gave Me" (2011) and called it "bombastic, humming with church-organ, jangling with tambourine and booming with Florence Welch's cannon-blast voice.

"[8] Laura Foster of Clash magazine wrote that the song was one of the six "massive" anthems on Ceremonials and praised the "power balladry".

[33] Alex Young of the website Consequence of Sound praised the anthemic nature of the song and concluded that the "sing-a-long-approved chorus takes over and it keeps you under its spell for the remaining three minutes.

"[9] Barry Nicolson of NME concluded that the chorus of the song "announces itself with a sudden, overpowering immensity akin to sheets of ice being atomised by a ruddy great hammer.

[20] Jillian Mapes of the same publication commented: "Welch's goth-pop allure is summed up in the chorus of the album's dramatic first single: 'It's hard to dance with the devil on your back, so shake him off.

"[36] Pitchfork Media's Carrie Battan chose the song as a "Best New Track" and added that it's "even more massively anthemic than the already-anthemic singles off Lungs.

Huge drum hits drive the track from the onset, and Welch's voice is in peak form throughout, nearly spilling over the edge as of the song.

she belts over crashing symbols and glittery synths on the chorus; the result, a good ol'-fashioned knees-up of a song that wouldn't sound out of place in an East London pub or the McKinley High stage.

"[38] Will Hermes of Rolling Stone called the song "mighty" and compared Welch's vocals with Glinda the Good Witch.

[39] Entertainment Weekly's Kyle Anderson commented that "Welch's soul is constantly in peril here, forcing her to dance away from devils" in the "swinging, jubilant" song.

[43] The writers of the website further commented, "If lyrics about freedom, overcoming regrets that have been collected 'like old friends here to relive your darkest moments,' and the simple truth that it's hard to dance with a devil on your back doesn't move you, then perhaps the final 60 seconds of 'Shake It Out' will, which forsakes language altogether and builds to a cacophony of bone-rattling organ, tribal percussion, and intersecting vocal parts that find Florence Welch finally succumbing to her demons and having drinks in the dark at the end of the road with the rest of us.

It features Welch wearing a red gown and singing while attending a 1920s-era masked ball,[50] evoking references to works such as Eyes Wide Shut,[51][52] The Great Gatsby and "The Lady of Shalott".

[4][54] Michael Roffman of the website Consequence of Sound, compared the video with the work by Madonna because of "the hazy cinematography and the choir-like theatrics.

"[55] RJ Cubarrubia of Billboard wrote that "although the video feels somewhat dark and mystical, like a secret society meeting with unsettling masks and a slightly possessed Welch, the vibe is ultimately joyful and inspiring, with the party guests and Welch visibly bursting with happiness by the video's end.

"[56] Larry Fitzmaurice of Pitchfork Media said, "the video is cinematic and features a really weird party where people are wearing masks.

[54] Spin's Marc Hogan wrote, "the video doesn't have the clearest plot, [but] it does depict Florence Welch dancing with masked, formally attired men, a visual that sparks comparisons to the posh orgy of Stanley Kubrick's film Eyes Wide Shut, but a bacchanal does not break out.