of the Burl". A seventeen-date European tour was announced that featured dates in Scandinavia, Germany, France, Spain, Belgium, Portugal, Italy, the Netherlands and Latvia. On December 1, "Curl of the Burl" was nominated for a Grammy Award in the category Best Metal/Hard Rock performance. It is the band's second nomination with the first being for "Colony of Birchmen" in 2007. The record was named "Album of the Year" by Metal Hammer, Classic Rock and Rock Sound. In January 2012 it was announced that Mastodon and Swedish prog metal band Opeth will tour together in a joint tour across North America. It was named the "Heritage Hunter Tour" after both bands latest releases, The Hunter and Heritage. The bands took turns in the headlining spot. Support came from the Swedish heavy metal band Ghost. On February 11, 2012, the band performed a sold-out show at the Brixton Academy in London, it was the band's biggest headline show ever. Dry Bone Valley" was released on February 13 as the third single of the album. A music video for the song was also released. On April 21, 2012, to commemorate Record Store Day, Mastodon released two separate vinyls. The first was a split 7-inch with Feist titled Feistodon. Mastodon covered Feist's "A Commotion" and Feist covered Mastodon's "Black Tongue". The pair also released a one of a kind interactive, crossfading music video for the song 'A Commotion'. The second release was a cover of The Flaming Lips' "A Spoonful Weighs a Ton". The band spent the summer performing at festivals across Europe and South America. It was the last tour in support of The Hunter. Once More 'Round the Sun (2014–2015) Mastodon began recording again in early 2013. Guitarist Brent Hinds described the new music as "really eerie" and "very spooky-sounding", and stated that he has written three new songs. On December 3, 2012, the band announced via their Twitter page that they were writing a song for the film Monsters University. However, the song used in the film was the previously released "Island". They were also part of the 2013 Rockstar Energy Mayhem Festival. On May 6, 2013, the band stated that they are "...Very busy writing and putting songs together for the next studio Mastodon album..." In an interview on July 26, Brann Dailor was reported as saying that the band would "probably [go into the studio] end of September". The