Nightmare (Halsey song)

"Nightmare" is described as an alternative rock,^[3] punk rock,^[4] emo,^[5] electro-metal,^[6] industrial^[7] and trap^[3] song by critics. It is written in the key A minor with 146 beats per minute.^[8] The song contains an interpolation of "All the Things She Said" by Russian duo t.A.T.u. Elena Kiper, one of the songwriters of t.A.T.u's song, posted on her Instagram that an initial version of Halsey's track "contained an extensive interpolation of the original work" but later the sample was changed by G-Eazy,^[9] although the latter isn't credited on the work.

In May 2019, Halsey posted a link on her social media, directing users to the website "nightma.re" to sign up for email alerts and prompting them to share what their worst nightmare is. The site gave a series of options, and upon clicking one of the options, users would be shown an explanation as to the meaning of that specific nightmare.^[10] Fans also believed that the time tickets for her recent intimate concerts went on sale, 5:17 PM, was a hint towards the date new music would be released,^[11] although Halsey claimed no knowledge of this and only said new music would be coming "sooner than you think".^[10] She then announced the single's release date on Twitter on May 9, 2019, posting a video of her revealing the title at one of her concerts, and captioning it "new single. NIGHTMARE. may 17th".^[1] Several days later, Halsey announced she had hidden lyrics of the song in five US cities: Los Angeles, Dallas, Chicago, San Francisco, and New York City.^[12]

On May 20, 2019, Halsey performed a free show for fans in Minneapolis, where she performed the single live for the first time, along with "Castle", "Gasoline", "Without Me" and "Don't Play". She uploaded a video of some of the performances on YouTube following the show.^[13]

The music video for "Nightmare" premiered on YouTube on May 16, 2019.^[14] Directed by Hannah Lux Davis, the video features appearances by Cara Delevingne, Debbie Harry,^[15] Ryan Destiny, and Suki Waterhouse.^[16]

The song has received positive reviews. Billboard magazine said the song is musically "unorthodox" containing "stylistic curveballs" and "killer lines" that "exalt autonomy, sexual freedom and self-acceptance".^[17] The line "I've been polite, but I won't be caught dead/ Letting a man tell me what I should do in my bed" was noted as a "barbed assault on patriarchal expectation" by Billboard and "a necessary gesture of rage and empowerment" by Rolling Stone.^[18] Billboard named it the 17th best song of 2019.^[19]

Credits adapted from Tidal.^[20]

• Halsey – vocals, songwriting
• Benny Blanco – production, songwriting, record engineering, keyboards, programming
• Cashmere Cat – production, songwriting, keyboards, programming
• Happy Perez – production, songwriting, guitar, programming
• Elena Kiper – songwriting
• Ivan Nikolaevich Shapovalov – songwriting
• Martin Kierszenbaum – songwriting
• Sergio Galoyan – songwriting
• Trevor Horn – songwriting
• Valerij Valentinovich Polienko – songwriting
• John Hanes – mixing engineering
• Serban Ghenea – mixing
• Chris Gehringer – mastering engineering

"Nightmare (Reprise)" is a song by Halsey included on the Walmart bonus track edition of her fourth studio album If I Can't Have Love, I Want Power (2021). The song is a re-produced version of "Nightmare" created to match the sound of the album. It was first teased by Walmart when a 25-second snippet of a censored version of the song was posted to their website as promotional material for their Walmart exclusive version of the album.^[68] It was later added to the extended edition of the album along with "People Disappear Here" and the original "Nightmare".