the Philippines for the annual Pulp Summer Slam on April 17, 2010 with Lamb of God. Dark Roots of Earth (2010–2013) As early as 2009, Testament started writing new material for their tenth album. In an interview with Metalheadz, Peterson stated that there were about four songs written and that "there's other guys in the band who like to play the more rock melodic style but the next one is gonna be a bit heavier." In a January 2011 interview during the 70000 Tons of Metal cruise, Billy revealed that Testament had been working on six new songs, with four or five "maybe left to write," and would begin recording their new album by early March. On May 18, 2011, Skolnick posted an update on his Twitter, saying, "Another tune done! My riffs from last week [plus] some of [fellow Testament guitarist Eric Peterson's] plus new ones we wrote today. Planning one more, then we've got more than we need." Testament began recording their tenth studio album on June 20, 2011. Paul Bostaph was unable to take part in the recording due to a "serious injury", although he was expected to rejoin when the band began touring to support the album. Bostaph was replaced by Gene Hoglan, who had played drums with Testament on their 1997 album Demonic. Testament appeared at the California dates of the summer 2011 Rockstar Energy Drink Mayhem Festival, replacing In Flames. The band toured in the fall of 2011 with Anthrax and Death Angel. Overkill was invited to the tour, but due to the pre-production of their sixteenth studio album The Electric Age, they did not participate. John Tempesta filled in for Bostaph on the tour. It was announced on December 1, 2011 that Paul Bostaph had left Testament. Gene Hoglan, who had recorded the drum tracks for the new album, was brought back after the band had expressed pleasure in his playing, hoping that he would continue with the band for the foreseeable future. After many delays, the band's tenth studio album Dark Roots of Earth was released on July 27, 2012. The album debuted at No. 12 on the Billboard 200, their highest chart position to date. Lamb of God drummer Chris Adler made a guest appearance on the bonus track "A Day in the Death". Dark Roots of Thrash and Brotherhood of the Snake (2013–2019) In August 2012, Peterson stated that Testament