In the near decade that the West Akron duo the Black Keys have been making records, they have experienced a steady climb in their commercial fortunes, international profile and artistic ambitions.
Through their first four albums, they honed their two-man scuzzy, blues rock stomp. But after 2006's Magic Potion, they knew they had to expand their sonic palette. They hooked up with hip producer and fan Brian ''Danger Mouse'' Burton and came up with the diverse Attack and Release, which proved to be the band's most successful record, debuting at No. 14 on the Billboard charts and garnering lots of positive press.
After the success of that album and tour, guitarist/singer Dan Auerbach and drummer Pat Carney took time to explore other musical avenues. Auerbach released his debut solo album Keep It Hid in 2009, toured and produced other bands, including the recently released album by bluegrass band Cadillac Sky. Meanwhile Carney joined forces with some local musicians/friends to form the anthemic indie supergroup Drummer, which released Feel Good Together the same year.
The pair also answered a call from hip-hop impresario Damon Dash to come to New York (where Carney now resides much of the year) for a ''collabo.'' The result was Blakroc, a pleasant album of head-nodding grooves with verses by rappers, including Q-Tip, RZA, Mos Def and Raekwon.
The Blakroc experience carried over into album No. 6, entitled Brothers, due in stores and online Tuesday. Carney and Auerbach returned to producing themselves, aided by engineer Mark Neill, and recorded for 10 days at the legendary Muscle Shoals studio in Alabama. They also spent a few days at Auerbach's Easy Eye Sound System in Akron and a one-day session with Danger Mouse in Brooklyn, to produce their longest album to date.
Often when a band chooses a title such as ''togetherness,'' ''unity'' or a similar word, it symbolizes some trial and/or tribulation that the members have recently experienced. Both Auerbach and Carney said the title fit their current state as longtime friends and band mates.
Auerbach said he wrote Unknown Brother (track 13) about his wife Stephanie's older brother, who died.
''I was talking to Pat about it because he loved the song and we both have brothers, and we couldn't imagine being 16 years old and losing your brother. And we had just gotten through a rough patch where [Pat] was coming out of his relationship and coming out of the fog and we were coming back together again after being away, so it just felt right. Pat said, 'Why don't we call the record Brothers?' and I was like, 'Wow, yeah, do it, man.' ''
''We were never on the verge of breaking up or anything, but we went through some normal [stuff], and now we got it all worked out and we're probably closer now than we have been, probably ever,'' Carney said from his working vacation in Laguna Beach, Calif.
''My head space was all [messed] up for a long time and it didn't really have anything to do with Dan or the band, but we got through that [stuff] and here we are.''
Brothers isn't as musically diverse as its predecessor, and any fans hoping for a return to the scuzzy riff-reliant blues of Rubber Factory will have to let go of their preconceptions. The album is more groove-oriented with a funky edge inspired by the Blakroc sessions, which the band had finished a few days before going to Muscle Shoals.
''We've always listened to hip-hop, but I was pretty obsessed with early '70s soul — the Invincibles, the Impressions — and was listening almost exclusively to that and hip-hop when we started to make the record,'' Auerbach said.
Though they included bits of sonic accoutrements throughout their catalog, for Brothers, they altered their usual recording blueprint of starting with drums and guitar, with Auerbach playing bass and both splitting keyboard duties.
''There are still lots of riffs, just not so much guitar riffs,'' Carney said. ''We were more interested in working stuff out with the bass and drums first, then keyboards and exploring the groove rather than just establish the groove, so, yeah, there's a little less riffage.''
Both the hip-hop and classic soul influences run through the album, evidenced in songs such as the slinky, stomping, funky, bass line of Sinister Kid; the syncopated beat of the Danger Mouse-produced lead single Tighten Up; the organ- and electric piano-laden soulful grooves that anchor the slow-boiling kiss-off I'm Not the One; and its thematic polar opposite, The Only One.
On the latter song, Auerbach introduces fans to his surprisingly sweet falsetto voice, another by-product of his soul and hip-hop obsession.
''Watching all those different rappers do their thing on the microphone, it helped me to loosen up a little bit and try things I've never done before,'' Auerbach said.
''I've sung falsetto harmony a bunch, but I never thought to do it as the lead vocal. But the combination of listening to 1971 soul music where every black singer in America seemed to sing in falsetto, and being inspired by the Blakroc thing, where they just let it all hang out, I just went for it.''
That doesn't mean Auerbach has retired his library of fuzz and effects pedals. There is some heavy riffage to be found, highlighted by She's Long Gone, which Carney calls ''one of the thickest riffs that Dan has ever written.'' It also shows up on the garagey Howlin' for You, which borrows the familiar thump of Gary Glitter's stadium staple Rock and Roll, Pt. 2.
Though the disc's lone cover — Jerry Butler's classic ballad Never Gonna Give You Up — could have been left as a B-side or iTunes ''exclusive,'' Brothers is the Keys' funkiest, grooviest record yet and a continuation of their desire to continually stretch their own musical boundaries.
Their label, Nonesuch, is excited about Brothers, as is the label's corporate overlord Warner Bros., which will be giving the record the biggest promotional push the band and the label have ever received. The Keys will appear on Late Show With David Letterman and Late Night With Jimmy Fallon on May 25 and 26, respectively. When the touring cycle begins in June, the Keys will be performing in front of thousands of potential new listeners, nabbing an opening spot for Pearl Jam at Madison Square Garden. They were also invited to open a bunch of dates with the Kings of Leon.
''Yeah, the Kings of Leon thing is crazy, because we'll be playing sheds in front of 20,000 people that probably don't know us, so that's pretty huge,'' Auerbach said.
Their commercial ante may be going up, but they have been at it too long to be nervous. Besides, they aren't intimidated by the idea of gaining more notoriety.
''I've dealt with a 21/2-year-old child every day, and it's a full time job without a doubt,'' Auerbach said, referring to daughter Sadie.
The Black Keys will also be expanding their onstage sound for the first time, with the addition of two extra musicians to help fill in the bass and keyboard parts on the newer songs.
But in the end, it all comes down to the two finding themselves in the best ''head space'' as friends, band mates and brothers from other mothers.
''In a way, every time we make a record, we get more and more in-depth together in how we operate,'' Carney said.
''Making this record with an engineer — one song had a producer, but for the most we produced it ourselves — it was good for us to sit down and communicate,'' he said. ''To sort out what we wanted to accomplish together and have direct lines of communications. It was good.''
Malcolm X Abram can be reached at firstname.lastname@example.org or 330-996-3758.