Opposites is the sixth studio album by Scottish alternative rock band Biffy Clyro, which was released on 28 January 2013. A double album, Opposites was originally announced as a pair of albums: The Land at the End of Our Toes and The Sand at the Core of Our Bones, these will now be the names of the individual discs on the albums. Band of Horses' Ben Bridwell features as a guest vocalist on the songs "Opposite" and "Accident Without Emergency". The album features 20 songs across the two discs although a single disc version with 14 selected tracks also exists. The single 'Biblical' was featured first on Zane Lowe's show on BBC Radio 1 in the U.K and on Gary Cool's Rock Dimension in S.A. More than three years between Only Revolutions and Opposites mark the longest gap in Biffy Clyro's publishing history. During this time, the band's rising popularity saw them perform an increasing amount of shows, which delayed the work on the new album. The band had been reported to work on the new songs as soon as the spring of 2010. In March 2011, Simon Neil told BBC that he had "15 or 16 songs" ready for the album and that the record would get done "as soon as [they] got off the road". The band played the first new song to later appear on Opposites, entitled "Joke's On Us", on 3 July 2011 at Milton Keynes, in what was set as one of their last gigs before heading to the studio. Opposites main recording sessions started in early 2012 and lasted for five months at The Village Studios in Los Angeles. The producer was GGGarth Richardson, returning to the work with Biffy Clyro after producing two previous albums, Puzzle and Only Revolutions. Also returning from Only Revolutions was the orchestra and choir conductor, David Campbell. The keyboard parts were made by Jamie Muhoberac, who also performed on Only Revolutions. In May 2012, NME announced that the band is going to release two albums, The Land and the End of Our Toes and The Sand at the Core of Our Bones. A month later, it was reported that the band "changed their mind" on the double title. Simon Neil revealed the album's final title on 31 July 2012 on Zane Lowe's show on BBC Radio 1. The release date has been announced on 18 September 2012 on Biffy Clyro's website. In an interview with Q, the band claimed to have had written 45 songs by the end of 2011. That number was said to give them a feeling of necessity to make Opposites a double album. "There's no filler on this one", Ben Johnston assured in an NME feature. "We wanted to make the first double album that you could enjoyably listen to from start to finish", said Simon Neil on Zane Lowe's show on BBC.