Eternal Blue is the debut studio album by the Canadian heavy metal band Spiritbox. It was released on September 17, 2021, through the band's label Pale Chord Records in partnership with Rise Records. Vocalist Courtney LaPlante and guitarist Mike Stringer formed Spiritbox in 2016 following their departure from Iwrestledabearonce. After revealing the project and releasing an extended play (EP) in 2017, Spiritbox began development on Eternal Blue in 2018. In the meantime, the band recorded several other singles that were compiled into a second EP in 2019. Their first full-length record was scheduled for an April 2020 release but development and promotion were initially halted due to the COVID-19 pandemic.

After releasing "Holy Roller" and "Constance" as singles in the latter half of 2020, Spiritbox relocated to Joshua Tree, California, in early 2021 and completed songwriting for the album. Stringer and former Volumes guitarist Daniel Braunstein produced the project, and Braunstein finished the recording in early March 2021. Eternal Blue includes several metal genres and subgenres, and electronic elements, and LaPlante used both screamed and clean vocals on the album. The album includes influences from Slipknot, Deftones, Depeche Mode, Tears for Fears, and several other artists. The project is the only studio album Spiritbox released while bassist Bill Crook was a member of the band, though he did not play any bass parts on the album. He left the band in May 2022.

Once recording was completed, three more songs were released as singles prior to the album's release: "Circle With Me", "Secret Garden", and "Hurt You". All five singles from the album reached the American Billboard charts, and the album received universal acclaim from music critics, who praised its production, songwriting, and musicianship. Eternal Blue also charted in eight other countries and debuted at number thirteen on the Billboard 200, and numerous publications placed the album on their yearly best-of lists.

In 2015, the engaged couple Courtney LaPlante and Mike Stringer were members of the American metalcore band Iwrestledabearonce. LaPlante had joined the band in 2012 to replace vocalist Krysta Cameron, who had departed mid-tour; Stringer eventually joined the band as a guitarist and played on their final album Hail Mary (2015). Uncomfortable with being replacement members and wanting to pursue a new personal and creative direction, Stringer and LaPlante chose to leave the band in late 2015. Following their marriage, LaPLante and Stringer announced their new project, Spiritbox, on October 9, 2017.

As Spiritbox, LaPlante and Stringer released the single "The Beauty of Suffering", which was followed by a seven-song, self-titled debut extended play (EP) on October 27, 2017. Their former Iwrestledabearonce bandmate Mikey Montgomery played drums on the EP. Bill Crook of the pop-punk band Living with Lions joined the group as a bassist, and Shreddy Krueger's drummer Ryan Loerke became the band's first permanent drummer.

Throughout 2018 and early 2019, Spiritbox debuted five singles that were later compiled into an EP titled Singles Collection, which was released on April 26, 2019; the EP was followed by the non-album songs "Rule of Nines" in 2019 and "Blessed Be" in 2020. The tracks were all self-recorded with personal equipment, although they were mixed and mastered in another studio.

Loerke departed from Spiritbox in 2020, and was replaced by the Philadelphia-based drummer Zev Rose. According to LaPlante, the band members met Rose only two days before the band began performing with him on a short-lived tour, which was cancelled in March 2020 due to the COVID-19 pandemic.

The songwriting for Eternal Blue commenced several years before its release; most of the songs were written in 2018 and 2019. "Holy Roller" was written in January 2020 and Spiritbox debuted the unfinished track on a European tour in March. The album was initially scheduled for an April 2020 release but recording was interrupted by the COVID-19 pandemic. Spiritbox released "Holy Roller" as a single in the meantime. In September 2020, the band announced they had signed with Rise Records as part of their partnership with Spiritbox's vanity label Pale Chord Records. Spiritbox started pre-production on the album with their producer, former Volumes guitarist Daniel Braunstein, via the video-conferencing platform Zoom. The band released several music videos to promote the album, which proved popular among fans and increased anticipation of the album.

In January 2021, Revolver named Spiritbox's upcoming full-length release as one of its "60 Most Anticipated Albums of 2021". The band reconvened in Joshua Tree, California, to work in "their own bubble", which allowed them to continue writing songs and revise existing material together during the pandemic. The band set a deadline of April 2021 to finish work on the album so it could be released by the end of the year. Although Crook was an official member of Spiritbox, he did not record any bass parts for the album; Stringer played them instead. Crook did record some backing-vocal performances on the album. Eternal Blue was produced by Braunstein and Stringer. Braunstein recorded it with the band in complete isolation at an Airbnb rental house located on a 20-acre (8.1 ha) desert property in Joshua Tree, referred to as the Old Heard Ranch in the album's credits. Eternal Blue was recorded over three weeks in February and the process was finished on March 1.

Spiritbox used several heavy metal-based musical styles on Eternal Blue; critics have described the album as metalcore, progressive metal, djent, post-metal, and alternative metal. The record was also labelled "post-metalcore" and a "nu-metal-meets-djent riff-fest". Near the debut record's release, LaPlante defined Spiritbox as a metalcore band. The band's use of digital synthesizer is prominent on Eternal Blue, displaying sounds ranging from atmospheric to industrial. This approach led Guitar World to describe Spiritbox as "digitally infused metal". In a post-release interview, Spiritbox said they were inspired by the 1980s pop music scene, Nine Inch Nails, and early post-punk bands such as The Cure during the album's production, and minimalist, "airy" song structures that are characteristic of 1980s dark rock are an important base to the music on Eternal Blue. According to Stringer, the band disregarded genres during the making of the album and focused on what they enjoyed playing, adding: " ... the whole time, we were just thinking, 'Who cares if this song is similar to a Billie Eilish song and this song is the heaviest song we've ever done outside of 'Holy Roller'? It doesn't matter, it all belongs in the same body of work.'"

LaPlante both screams and sings throughout Eternal Blue. Stringer had often played a "dissonant, spastic, crazy, 'how many notes can you fit in a riff?' style of music" in his previous bands, and made a concerted effort with Spiritbox to diversify his approach into one that yielded stronger, full tracks rather than a small portion of a song, whether atmospheric or heavy in nature. In a post-release interview, Stringer stated Spiritbox's music was never played higher than drop F#, and was occasionally recorded in lower tunings. Tunings were frequently changed, sometimes within songs; on "Holy Roller", tunings were changed four times through the use of a pitch shifter.

LaPlante, who wrote most of the lyrics on Eternal Blue, explored themes of frustration and sadness. She told Exclaim! that she usually feels more comfortable writing about "the things that upset me or make me feel self-conscious and insecure in metaphor". The album and its title track take their name from EternalBlue, a computer exploit the United States' National Security Agency (NSA) developed. While cybersecurity is not one of the album's themes, LaPlante used the term to refer to the mood of the album's content.

The opening track of Eternal Blue, "Sun Killer", was written in January 2020. The song crates a dramatic atmosphere in which LaPlante envisions a band's entrance to a live show, and thus was chosen to open the album. "Hurt You", which was also written in early 2020 prior to the COVID-19 pandemic, is a nu metal song that explores the feeling of a choice to stay in a doomed romantic relationship that is riddled with "toxic co-dependency". According to LaPlante, the song's working title was "Heavy Clown", a reference to Shawn "Clown" Crahan of the nu metal band Slipknot and alluding to the song's self-described "nu metal references". LaPlante described "Yellowjacket" as "inhumanly heavy"; throughout the song, her vocal performance alternates between her "scariest" screams and normal speech. The use of speech was inspired by the works of 1990s alternative rock bands, such as Butthole Surfers, who used the technique. "Yellowjacket" contains a performance from the vocalist Sam Carter of Architects, which is the only guest appearance on the record. LaPlante initially did not want any guests to appear on the album, citing travel difficulties during the pandemic and a desire to prove herself as a capable vocalist without outside exposure. During the project's recording sessions, Carter contacted Spiritbox and offered to feature on a song, which became "Yellowjacket".

"The Summit" is an attempt to bend musical genres in a way "that doesn't make sense"; LaPlante found defining the song as heavy metal was difficult. Her vocal performance took inspiration from the music of Charli XCX and the Weeknd. In an interview with the Michigan Daily, Stringer named "The Summit" as his favourite song on Eternal Blue, highlighting its catchiness. "Secret Garden", which was written in mid-2019, showcases what LaPlante called the "fluidity that is inherent in heavy music" and the diverse metal styles of Spiritbox. LaPlante noted the distinction of "Secret Garden" as "just one part of a full body of work that may not sound exactly like this song". She highlighted how the band took influences from the music of Deftones in the "romantically sorrowful" song; its working name was "Chino", referencing Deftones' frontman Chino Moreno. "Silk in the Strings", a more-intense song, was created later in the writing process. LaPlante was initially unsure how to proceed with the song after Stringer showed her the musical concept; for her vocal performance, LaPlante embraced a rapper's perspective rather than one of a heavy metal frontwoman, imagining how Wu-Tang Clan would rhythmically approach the song.

"Holy Roller", which one critic described as Spiritbox's heaviest song and "far darker and more violent" than any of their previous material, is themed around religion and contains references to Christianity. In her lyrics, LaPlante takes the role of the Devil, speaking internally to the listener as a sort of personified evil. Stringer's performance on the song includes a pick-scrape technique that has been likened to the work of Gojira. The title track "Eternal Blue" was one of the first songs the band wrote for the album. Braunstein helped the band explore new wave influences on the track, among them Depeche Mode and Tears for Fears. LaPlante wrote the song's lyrics, which are about a real-life experience; the song was inspired by a difficult break-up of a friendship and the coming-to-terms with its end. "We Live In a Strange World" was also written before the COVID-19 pandemic; LaPlante wrote the lyrics as an introspection on the recognition Spiritbox was beginning to gain and her fears of "messing it up".

"Halcyon" creates a dramatic atmosphere similar to "Sun Killer", though catchier, according to LaPlante. Its lyrics describe the pressure on her to be successful with her music. "Circle with Me" was the final song written for the album; it was completed in the recording studio. The lyrics describe LaPlante's emotional journey from feeling anxiety "about messing up" her music to empowering self-confidence. The song includes "breathy vocals" and melodies that mixing guitars with electronic instrumentation, contrasting with harsher parts and a breakdown. The closing track, "Constance", takes an ethereal approach to metal one critic described as "the polar opposite" of "Holy Roller". The song is dedicated to LaPlante's grandmother, Phyllis; because of the pandemic, LaPlante could not say a last goodbye to Phyllis before her death nor attend her funeral. The song's namesake is Constance, the grandmother of the music video's director, Dylan Hryciuk. Constance, to whom the video is dedicated, was in late stages of dementia at the time of its release.

On May 25, 2021, Eternal Blue was announced for release; in the following 24 hours, the band sold 6,500 vinyl pre-orders. Eternal Blue was released on September 17. Spiritbox attempted to tour again in July 2021, supporting Limp Bizkit in the US; this tour was also cancelled after a few dates due to safety concerns involving the pandemic. This aborted tour cost the band many unexpected expenses; Shinedown singer Brent Smith offered Spiritbox $10,000 to help cover lost tour expenses and We Came as Romans waived rental charges for their lighting package. According to Stringer, Smith was empathetic and did not want Spiritbox to collapse due to financial hardship. Smith decided to donate despite having never met the band before.

With the exception of an appearance on the Coheed and Cambria-headlined S.S. Neverender cruise in October 2021, Spiritbox did not begin live performances in support of the album until 2022, when they were a special guest on Underoath's Voyeurist tour in February and March, joining Bad Omens and Stray from the Path. In May, it was announced Spiritbox had joined the second leg of Ghost's Imperatour alongside Mastodon through August and September 2022. Crook left Spiritbox shortly after the tour's announcement and was replaced by former As I Lay Dying bassist Josh Gilbert. Spiritbox played their first live show in the United Kingdom in June 2022 at Download Festival. The album's official headlining tour of the United States did not proceed until April 2023 with guests After the Burial and Intervals.

Spiritbox first found critical and commercial success with "Holy Roller", which was released on July 3, 2020. The band worked with Revolver to premiere the single and an accompanying music video. The song debuted at number 25 on the US Billboard Hot Hard Rock Songs chart and rose to number 12 six months later. The song's original version spent seven weeks as number one on Sirius XM Liquid Metal's radio chart show Devil's Dozen, and the station's listeners deemed it the best song of 2020. In October, Spiritbox released a remix of "Holy Roller" that features Ryo Kinoshita of Crystal Lake. The remix spent five weeks at number two on Sirius XM Liquid Metal's Devil's Dozen. "Holy Roller" was later covered by a nine-year-old girl named Harper on the 17th season of America's Got Talent; the show's judges gave Harper a resounding positive reception and she performed the song live with the band in London.

On December 4, 2020, Spiritbox debuted the ballad "Constance", which earned Spiritbox further acclaim from critics and the metal community for showing the band's stylistic versatility. In retrospect regarding "Constance", Loudwire hailed Spiritbox as "one of the most buzz-worthy rising bands in heavy music", and Rock Sound found the track defined "the variety that exists within their music with slowburning and emotional composition". The third single from Eternal Blue was "Circle With Me", the final song to be written for Eternal Blue. "Circle With Me" was released on April 30, 2021, with its music video, which was directed by Orie McGinness. In mid-May, the single topped the US Billboard Hard Rock Digital Song Sales chart, reached number five on the US Hot Hard Rock Songs, number 12 on the US Rock Digital Song Sales, number 50 on the US Hot Rock & Alternative Songs, and number 71 on the US Digital Song Sales chart.

"Circle With Me" was followed by "Secret Garden" on May 25; the track peaked at number 34 on the US Billboard Mainstream Rock chart in mid-August. During the first week of August, "Constance" garnered enough public attention to stay at number one on the US Billboard Hard Rock Digital Song Sales chart and reach number 19 on the US Billboard Hot Hard Rock Songs. One final single, "Hurt You", was shared on August 20 in advance of Eternal Blue. Hryciuk directed the music video. "Hurt You" charted at number 20 on the US Billboard Hot Hard Rock Songs in the week of September 4, 2021.

Professional ratings

Aggregate scores
Source	Rating
Metacritic	84/100
Review scores
Source	Rating
AllMusic
Kerrang!	5/5
Kill Your Stereo	75/100
Metal Hammer
New Noise Magazine
Outburn	10/10
Rock Sins	9/10
Sputnikmusic	4.1/5
Upset Magazine
Wall of Sound	8.5/10

According to review aggregator Metacritic, Eternal Blue received "universal acclaim" based on a weighted-average score of 84 out of 100. Kerrang! reviewer Steve Beebee highlighted "dreamlike soundscapes" on "Secret Garden" and "The Summit", and the heaviness of "Silk in the Strings" and "Holy Roller" as evidence of the album being the best release of 2021. Owen Morawitz at New Noise Magazine highlighted the album's songwriting and musical versatility, particularly those on "Eternal Blue" and "Halcyon", as reasons to believe the album could attract the most-skeptical listeners. AllMusic's Neil Z. Yeung noted fans of Tesseract, Deftones, and Meshuggah would enjoy the album, particularly comparing "Circle With Me" and "Eternal Blue" to these groups' works. Steven Loftin of Upset called Eternal Blue "simultaneously familiar and fresh".

Outburn's Nathan Katsiaficas also gave special praise to "Halcyon", which he said encompasses all of the dynamics on the album. He called the record a "modern metal masterpiece", and said the songwriting and musicianship on it create "an absolute thrill ride from start to finish". Wall of Sound reviewer Paul Brown likened listening to Eternal Blue to a musical journey, saying it "connects with the listener on an emotional level and takes them on a journey of self-discovery, empathy and overcoming". Writing for Rock Sins, Simon Crampton summarized the album as "one of the most self assured, emotionally enriching and musically diverse albums of the year", noting the strength of Spiritbox's work is the band's ability to "mix the heavy & heartfelt".

According to Alex Sievers of Kill Your Stereo, while Eternal Blue has some flaws, including the overuse of atmospheric effects, he praised its diversity, noting the contrast between the brutality of "Holy Roller" and the cleaner, atmospheric nature of "Constance". He also placed "Secret Garden" among the album's strongest material, particularly enjoying its hook. Metal Hammer's Dannii Leivers noted that, while Spiritbox's combination of heavier and gentler sounds was not a new concept, the material on Eternal Blue carries an emotional tone that improves its appeal. She concluded: "Eternal Blue is a staggeringly brilliant record that resoundingly delivers on the hype". Robert Garland at Sputnikmusic stated: "As easy as it would be to simply lump on the praise for Spiritbox's debut ... Spiritbox have more yet to offer, more growth, more great tracks and, if we're lucky ... they might even hit all that growth on a sophomore release".

Eternal Blue entered the Billboard 200 chart at number 13 with 23,000 album-equivalent units earned in the United States, of which 19,000 were pure album sales, in the tracking period September 17–23. The album ranked third on the Top Album Sales chart in the week ending October 2, 2021. The album also charted at number 8 on the Top 50 Albums Chart in Australia, number 17 in the Top 100 Albums chart in Germany, and at number 19 on the Official Albums Chart Top 100 in the United Kingdom, although it was placed at number 8 mid-week on the UK chart on September 20, 2021. Eternal Blue peaked at number one on both the Australian ARIA Top 20 Vinyl Album chart and the US Billboard Vinyl Album Sales chart, and at number 2 on the UK Official Vinyl Albums Chart. It reached number 2 on the US Independent Albums chart and number 12 on the US Tastemaker Albums chart in the week of October 2, 2021. Eternal Blue went on to sell over 175,000 copies worldwide in one year.

Publication	Country	Accolade	Rank	Ref.
Consequence	US	Top 30 Metal and Hard Rock Albums of 2021	14
Exclaim!	CAN	Exclaim!'s 50 Best Albums of 2021	10
Guitar World	US	The 20 Best Guitar Albums of 2021	13
Kerrang!	UK	The 50 best albums of 2021	2
Loudwire	US	The 45 Best Rock + Metal Albums of 2021	1
Loudwire	US	The 35 Best Metal Songs of 2021 ("Circle With Me")	2
Metal Hammer	UK	The top 10 metalcore albums of 2021	1
PopMatters	US	The 10 Best Progressive Rock/Metal Albums of 2021	7
Revolver	US	25 Best Albums of 2021	2

Credits are adapted from the album's liner notes.