While 2002's Songs for the Deaf was said to be inspired by Josh Homme's tedious drive through the Southern Californian desert, the inspiration for Era Vulgaris came from Homme's daily drive through Hollywood. He described the record as "dark, hard, and electrical, sort of like a construction worker," "…it's like dirt, clearly seen." The album's title Era Vulgaris refers to the Latin term for Common Era. The title was chosen by Homme because he thought "it sounds like 'the Vulgar Era', which I like, because that sounds like something that I would like to be part of… I mean I think we're in it, and I'm stoked".
Two tracks from the album had previously been released or performed elsewhere. "Into the Hollow" had been performed by producers Josh Homme and Chris Goss as The 5:15ers, and "Make It wit Chu" had been recorded as a Desert Sessions track, as well as appearing on the Queens' live album Over the Years and Through the Woods.
In June 2006, in an interview on the Australian radio station Triple J, Jesse F. Keeler, the bassist from Death from Above 1979, revealed that he would be playing bass on an upcoming Queens of the Stone Age album, but said that he would more than likely not be touring with the band due to his desire to spend more time with his girlfriend. Eventually on the DFA internet forum, Keeler revealed that due to conflicting schedules, he would not be appearing on the album. In a July interview with NME, Homme confirmed that the band was back in the studio, writing, but he remained unwilling to reveal who would appear in the band on the new record:
That's not a healthy question. You'll ruin the surprise. We've gotta keep our cool.
The album was expected to include guest performances by Trent Reznor from Nine Inch Nails, Julian Casablancas from The Strokes, former band member Mark Lanegan, Billy Gibbons of ZZ Top, and (jokingly) deceased humorist Erma Bombeck. Of these, however, only Casablancas' and Lanegan's tracks appear on the U.S. release: Casablancas performed synth guitar and backing vocals on "Sick, Sick, Sick", and Lanegan sang backing vocals on "River in the Road". Ultimately, scheduling conflicts prevented Gibbons from appearing, while Reznor's track "Era Vulgaris" was released separately on the You Know What You Did promotional CD and the UK edition of the album.
The album was recorded "with exactly zero input from [record label] Interscope Records" between July 2006 and April 2007 at Cherokee Studios, Hollywood, Steakhouse Studios, Los Angeles and Sound City Studios, Van Nuys and mixed at Bay 7 Studios, North Hollywood, California. The album was recorded and mixed by Alain Johannes, while it was produced by Josh Homme and Chris Goss as the Fififf Teeners. The primary contributors to the recording were Homme, Troy van Leeuwen, Joey Castillo, Johannes and Goss.
We basically started a year ago. And like I said, we didn’t really have anything written. So it was a long process. It was the longest I've ever taken to make a record, frankly. I've made records over the process of a year but this was the first time it's ever been my total focus for that long. This was the first time I've ever done that...total focus for 10 months.
Goss and Johannes were replaced by Dean Fertita (keyboard) and Michael Shuman (bass) for later bonus track recordings and the subsequent supporting tour. Regarding the band's line-up changes for Era Vulgaris, Homme commented, "I like combinations that no one would expect… It's the cool part of any surprise party."
Era Vulgaris displays influences from many different genres. The album departs from the softer, hollowbody guitar sound of their previous album Lullabies to Paralyze with heavy, crunchy guitars and adding in some electronic influences. Rolling Stone noted the influence of "New Wave synth geek Gary Numan…all over this record." Musically, the album has been described as "brand new retro", a fusion of "punk, rock, blues and southern grit" (FHM), and slower, moodier, and groggier than the band's previous efforts.
Shortly after the album's announcement in February 2007, a video was posted on the band's official website showing Homme, Castillo and Van Leeuwen jamming. Along with brief footage of the recording session for "Misfit Love", the last 6–7 seconds of the video contained footage of the recording of "3's & 7's" accompanied by studio-mastered audio. A second video of the recording of the album surfaced subsequently on YouTube, depicting the band (this time including Alain Johannes) recording a new track, "Turning on the Screw" in studio.
In early April, the official band website was updated with a 37 second excerpt from "Sick, Sick, Sick". This was replaced by the complete song, "3's and 7's", which was later removed. QOTSA fansite thefade.net announced a promotional contest for fans to win "a special package" from the band, confirmed as legitimate by the band's webmaster. On April 13, packages were sent to selected winners containing a CD entitled You Know What You Did with the sole track "Era Vulgaris", which Homme separately confirmed would not be appearing on the record, although it was included as a bonus track on the UK edition. The CD was accompanied by a handwritten letter asking fans to share the song in any way possible:
Hello friend -
Thank you for accepting this gift. Included you will find the will to dance & the song ERA VULGARIS. It was pulled from the new album (of the same name) so that it could be to you and become an example of how we think "from now on" should be. As in - We do for you, you do for us.
So to start this relationship off, we have done for you. Now we ask this in return. Share this with friends you think we (you & us) would enjoy. Upload it and spray it like time released graffitti (sic) on the websites of places it does not belong.
Is it a new recipe on Rachel Ray's site? Is it a new Nickelback song on their board? A secret Gov't document? Video game cheats? Sex site password? Fuckin' whatever? You decide. Then tell us how you shoved this song into the guts of the internet & we (both) can smile wide with pride at our new relationship.
OH, but not till after midnight tonight... from now till then, is just for us. Can we trust you to wait? Relationships are built on trust. Enjoy!
The full track "Sick, Sick, Sick" was leaked onto the Internet, countered by the posting of a promotional video to the official site featuring a "sales pitch" for Era Vulgaris by two talking lightbulbs , followed by a streaming of "Sick, Sick, Sick" with official lyrics displayed in the background.
On May 2, 2007, Homme, Van Leeuwen and new band member Dean Fertita appeared on London radio station Xfm, performing an acoustic set that included the tracks "3's & 7's", "Into the Hollow" and "Suture Up Your Future".
It was announced that tracks from the band would appear in the video games Madden NFL 08, Guitar Hero III: Legends of Rock and Rock Band, specifically that the track "3's & 7's" would be featured in Madden NFL 08 and Guitar Hero III: Legends of Rock. Both "3's & 7's" and "Sick, Sick, Sick" are available as downloadable content on Rock Band and Rock Band 2, as they share the same Music Store. In addition, "Make It Wit Chu" was later included in the tracklist of Guitar Hero 5.
The album's cover features the two lightbulbs from the promotional video, Bulby and his pirate accomplice (pictured right), marking a change from the plainer designs of the bands' previous albums. According to Homme, the light bulb represented "…what you perceive to be a great idea that really is not that great of an idea". The cover was a slip of paper, with a simplified credits page on the back side, marked with the outline of the record. The typography follows an Old English style font; Blackmoor, with the 'Spermy Q' seen on their album Songs for the Deaf.
An art booklet was also included, featuring "Bulby" and several other characters which unfolded to display a pin-up advertisement for the album, following the 50's advertising satire as the rest of the album art followed. The lack of liner notes for the album was remedied when the official website allowed users to view an e-booklet, containing more detailed liner notes, lyrics, and previously unseen artwork. The green light bulb with the pirate hat, eye patch and peg leg is known as "Stumpy".
Some copies of the album cover contain a red and yellow rectangle spoofing the Parental Advisory seal, reading "Rental Advisory: Freedom Not for Purchase". Coincidentally, it was the first Queens of the Stone Age album since Rated R to not bear a genuine Parental Advisory seal.
The lightbulb characters were created by Morning Breath Inc. with overall art direction from Jason Noto and Doug Cunningham of Morning Breath Inc.
Reviews for the album were generally positive, earning a rating of 75 out of 100 on Metacritic, a decline from their previous two studio albums. Uncut and Allmusic's reviews were particularly glowing, with the latter noting how Era Vulgaris is "as different from Lullabies as that was to their dramatic widescreen breakthrough, Songs for the Deaf". Originally awarding the album with a four-and-a-half star rating, Allmusic changed this to a four-star rating in 2013, upon the release of the band's follow-up, ...Like Clockwork.
The Observer also commented on the album's change in direction, commenting that the band had "turned its back on the mainstream" and that the album was "uneasy and brooding" and "Gripping stuff". Rolling Stone gave the album four stars for the first time since the band's self titled debut, commenting that "Era Vulgaris is Homme's fifth Queens album, and like the others, it's intricately crafted, meticulously polished and ruthlessly efficient in its pursuit of depraved rock thrills." New York Times critic Jon Pareles selected the album as the 10th best release of 2007.
A number of reviews were negative, however; Q magazine gave the album two stars out of five, while The Village Voice criticized Homme for lack of originality, describing the record's sound as "listless and drained of ideas". The Guardian slated the record as lyrically clichéd and lacking the input of former bassist Nick Oliveri, and Entertainment Weekly delivered the closing indictment that "there isn't a single song here that you'll remember, or want to return to, two summers hence."
Era Vulgaris had sold 198,000 copies in the US, and 521,000 copies worldwide before falling off the charts. The US sales are a decline from their previous album, as Lullabies to Paralyze, had sold 342,000 copies in the US by March 2007. Neither album achieved the commercial success of the band's 2002 release, Songs for the Deaf, which had sold 986,000 copies in the US alone as of June 2007.
All tracks were written by Joshua Homme, Troy Van Leeuwen and Joey Castillo, except for "Sick, Sick, Sick" (Homme, Goss, Van Leeuwen, Castillo) and "Make It wit Chu" (Homme, Johannes, Melchiondo).
According to the album liner notes, the contributors were as follows:Josh Homme – lead vocals, guitar, backing vocals ("Make It wit Chu"), lead guitar (tracks 1,3,7,8), acoustic guitar ("Battery Acid"), percussion ("Turnin' on the Screw"), bass (tracks 4-6, 8-11), lap steel guitar ("Into the Hollow"), keyboard ("Into the Hollow"), electric piano (tracks 8 and 9), rhodes piano ("Make It wit Chu"), "badly tuned" piano ("Run, Pig, Run"), organ ("River in the Road"), "percussion ball" ("Run, Pig, Run")
Troy Van Leeuwen – keyboard (tracks 1,2,5,6), guitar (tracks 1-4,7,8,11), lead guitar (tracks 5,6,9), "crazy delay" guitar ("River in the Road"), lap steel guitar ("3's & 7's"), backing vocals (tracks 1,2,6,7), bass (track 2 and 7), "the percussion part that's a bitch" ("Turnin' on the Screw"), Moog ("I'm Designer"), rhodes ("Into the Hollow")
Joey Castillo – drums, percussion (track 1 and 7), "percussion ball" ("Run, Pig, Run")
Alain Johannes – bass (tracks 1 and 3), acoustic guitar ("Run, Pig, Run"), counterpoint guitar ("Misfit Love"), harmonic guitar ("Make It wit Chu"), counterpoint fiddle ("Misfit Love"), "cig" fiddle ("Run, Pig, Run"), marxaphone ("Run, Pig, Run"), backing vocals ("Run, Pig, Run")
Chris Goss – keyboard ("Into the Hollow"), "the chicken pluckin guitar" ("Turnin' on the Screw"), "twinkley bits" ("Sick, Sick, Sick"), organ ("Misfit Love"), electric piano ("Suture Up Your Future"), "eclectic" piano ("Battery Acid"), bass ("River in the Road"), backing vocals (tracks 7 and 11)
Julian Casablancas – casio guitar and vocals ("Sick, Sick, Sick")
Serrina Sims – backing vocals ("Make It wit Chu")
Brody Dalle-Homme – backing vocals ("Make It wit Chu")
Liam Lynch – backing vocals ("Make It wit Chu")
Mark Lanegan – harmony vocals ("River in the Road")
This list is exhaustive of the core eleven tracks (see above), but does not take into account contributions to bonus tracks.
Technical credits for the album are as follows:Chris Goss & Josh Homme (as The Fififf Teeners) − producers
Alain Johannes − engineer
Alain Johannes & Joe Barresi − mixing
Justin Smith − mixing assistant
Stephen Marcussen − mastering
Jason Noto − design, illustrations
Dr. Mark A. Williams − A&R